Method of producing volume hologram laminate

ABSTRACT

A method of producing a volume hologram laminate which can regenerate a hologram image in an arbitrary wavelength by a simple process. The method uses a volume hologram forming substrate which includes: a substrate, a volume hologram layer formed on the substrate and containing a photopolymerizable material, a resin layer, formed on the substrate so as to contact to the volume hologram layer, containing a resin and a polymerizable compound. The producing method includes processes of: a hologram recording process to record a volume hologram to the volume hologram layer, a substance transit process of transiting the polymerizable compound to the volume hologram layer, and an after-treatment process of polymerizing the polymerizable compound.

TECHNICAL FIELD

The present invention relates to a method of producing a volume hologramlaminate which comprises a volume hologram layer with a volume hologramrecorded. The present invention relates to a volume hologram laminatewhich comprises a volume hologram layer with a volume hologram recorded,a volume hologram transfer foil using the volume hologram laminate, anda volume hologram label. Further, the present invention relates to avolume hologram laminate excellent in forgery prevention (recyclingprevention) and in design, and a method of producing the same.

BACKGROUND ART

Holograms are those in which the wave front of an object light beam isrecorded as interference fringes in a photosensitive material by theinterference between two beams (object light beam and reference lightbeam) having the same wavelength. When a light beam having the sameconditions as a reference light beam used at the time of recordinginterference fringes is applied, a diffraction phenomenon by theinterference fringes is caused, and whereby the same wave front as thatof the original object light beam can be regenerated. Such a hologramcan be divided into some types (surface relief type hologram and avolume type hologram) by the recording faun of interference fringes.

Here, the surface relief type hologram is a type in which fineconvexo-concave pattern is engraved on the surface of a hologram layerto record a hologram. The volume type hologram, on the other hand, is atype in which interference fringes produced by the interference of lightare depicted three-dimensionally in the direction of the thickness asfringes differing in refractive index to record a hologram.

The volume type hologram can be mass-produced by using the hologramoriginal master, and therefore has an advantage of being better intechnical production compare to the relief type hologram. However,reality is that the laser beam used for technical production is limitedin their wavelengths. Therefore, the wavelengths of the light whichregenerate the hologram image of the volume type hologram mass-producedare also limited and it has been difficult to regenerate bright hologramimages in embodiments commonly using the holograms.

To respond to such problem, methods of changing the regeneratedwavelengths of the hologram images to the wavelengths different from thewavelengths of lights used at the time of recording the interferencefringes are recently used. In such method, an after-treatment to thevolume hologram layer where the interference fringes are recorded iscarried out, and thereby the period of interference fringes initiallyrecorded is changed.

In other words, since the regenerated wavelengths of the volume hologramare the same to the period of interference fringes recorded on thehologram layer, by changing the period of interference fringes recordedto the hologram layer afterwards, it is possible to change the period ofinterference fringes identical to the wavelengths of lights which arefrequently used in daily bases. Such methods to change the period ofinterference fringes recorded to the hologram layer afterwards is usefulin that it is possible to produce the volume hologram layers which canregenerate bright hologram images in common embodiments.

As such methods to change the period of interference fringes recorded tothe hologram layer afterwards, various methods are known. As a morecommon method, a method disclosed in the Patent Document 1 is introducedhere as an example. The Patent Document 1 discloses a method to enlargethe period of interference fringe by moving a monomer and/or aplasticizer contained in a layer to a volume hologram layer by carryingout a treatment such as a heating treatment through contacting the layercontaining the monomer and/or the plasticizer to the volume hologramlayer where the interference fringes are recorded. Such a method iscertainly effective in enlarging the period of interference fringes andto shift the regenerated wavelength to the long-wavelength side.However, on the other hand, it has problems such as offering fewvariable amounts in the period of interference fringe or making theprocess complicating.

Further, since the volume holograms can record information to thethickness direction, is means to record/regenerate the three-dimensionimages, and is expressed by light interference colors, it has anappearance not easily obtained by other image-forming means. Theproducing methods of the volume hologram are known, but copying of thevolume hologram is difficult because producing thereof requires asophisticated work using optical devices. Using such characteristics ofthe volume holograms, the volume holograms are used for prevention ofcopying the identification cards, bank card and others. The presentinventors have been discussing various methods as shown in PatentDocuments 2 and 3 to prevent forgery by making the peeling of volumehologram layer from the adhered identification card impossible so thatpeeling of which results in the breakage of the attached volumehologram. However, there is a possibility of allowing a copy of thevolume hologram when a contact copy by a single wavelength laser usingthe volume hologram laminate with a volume hologram recorded as anoriginal master is tried. Thus, a development of a volume hologramlaminate which makes a copy of the volume hologram difficult has beencalled for.

-   Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No.    3-46687-   Patent Document 2: JP-A No. 63-284586-   Patent Document 3: JP-A No. 2002-358018

DISCLOSURE OF INVENTION Problem to be Solved by the Invention

The present invention has been achieved in view of the above-mentionedproblems. The present invention provides: a method of producing a volumehologram laminate which produces in a simple process a volume hologramlaminate that can be reproduced in an arbitrary wavelength, a volumehologram laminate which can be produced in a simple process and whichcan regenerate a bright hologram image by controlling the regeneratedwavelength, and a volume hologram laminate the volume hologram of whichis not easily copied even when a contact copy by a single wavelengthlaser is tried and a method of producing same.

Means for Solving the Problems

To resolve the above-mentioned problems, the present invention providesa method of producing a volume hologram laminate using a volume hologramforming substrate which comprises: a substrate, a volume hologram layerformed on the substrate and containing a photopolymerizable material, aresin layer, formed on the substrate so as to contact to the volumehologram layer, containing a resin and a polymerizable compound,characterized in that the producing method comprises processes of: ahologram recording process to record a volume hologram to the volumehologram layer, a substance transit process of transiting thepolymerizable compound to the volume hologram layer, and anafter-treatment process of polymerizing the polymerizable compound.

In the present invention, by using a substrate, wherein the resin layerand the volume hologram layer are laminated so as they contact eachother, as the volume hologram forming substrate, by recording the volumehologram to the volume hologram layer in the hologram recording process,and then by transiting the polymerizable compound from the resin layerto the volume hologram layer in the above-mentioned substance transitprocess, it becomes possible to change the period of interferencefringes recorded to the hologram layer afterwards.

Accordingly, in the present invention, a volume hologram laminate whichcan be reproduced in an arbitrary wavelength can be produced by a simpleprocess.

In the present invention, the polymerizable compound is preferablytransited from the volume hologram layer. As the polymerizable compoundbeing transited from the volume hologram layer, for example, it ispossible to produce the volume hologram forming substrate of the presentinvention, after a resin layer made of only the above-mentioned resin isformed on the volume hologram layer by transiting a polymerizablecompound contained in the volume hologram layer. Thus, it becomespossible to carry out the method of producing a volume hologram laminateof the present invention by a simpler method. Further, as thepolymerizable compound is transited from the volume hologram layer,there may be cases where it becomes easier to transit the polymerizablecompound to the volume hologram layer in the substance transit process.

In the present invention, the photopolymerizable material preferablycontains a radically polymerizable compound and a cationic polymerizablecompound, and the polymerizable compound is preferably the cationicpolymerizable compound. Thereby, the volume hologram laminate producedby the present invention can be made to a laminate which can regeneratea hologram image with high contrast.

Further, by making the polymerizable material contained in the resinlayer and the constituent of the photopolymerizable material containedin the volume hologram layer identical, a volume hologram laminate canbe produced by even a simpler process in the present invention.

To resolve the above-mentioned problems, the present invention furtherprovides a volume hologram laminate comprising: a substrate, a volumehologram layer formed on the substrate and containing aphotopolymerizable compound, in which a volume hologram is recorded byforming an interference fringe, and a volume hologram-laminated partformed so as to contact to the volume hologram layer and comprising aresin layer which contains a transparent resin, characterized in that aninterference fringe is formed on the resin layer.

According to the present invention, because the interference fringe isalso formed on the resin layer, by arbitrary controlling the respectiveperiods of interference fringes formed on the volume hologram layer andthe resin layer, it is possible to obtain a volume hologram laminatewhich can regenerate the bright hologram image at an arbitrarywavelength. Further, because the resin layer is formed so as to contactto the volume hologram layer in the present invention, the volumehologram laminate of the present invention can be produced by, forexample, a method of simultaneously recording the interference fringesto the resin layer and the volume hologram layer after the volumehologram layer is directly formed on the resin layer. Thus, according tothe present invention, a volume hologram laminate which can be producedin a simple process can be obtained. Therefore, in the presentinvention, it is possible to provide a volume hologram laminate whichcan be produced in a simple process and which can regenerate a brighthologram image by controlling the regenerated wavelength.

In the present invention, a period of the interference fringe formed onthe volume hologram layer and a period of the interference fringe formedon the resin layer are preferably different. Because the hologram imagecan be regenerated at a wavelength which coincides with one of theperiods of interference fringe formed on the resin layer and the volumehologram layer, it thereby becomes possible to regenerate the hologramimage at plural regenerated wavelengths so that the volume hologramlaminate of the present invention can be made to the laminate which canregenerate brighter hologram image.

Further in the present invention, a transmittance in visible light rangeof the volume hologram laminate has preferably at least 2 minimaltransparent wavelengths. Thereby, the volume hologram laminate of thepresent invention can be made to a volume hologram laminate which canreproduce a further bright hologram image.

The present invention provides a volume hologram transfer foilcomprising: the above-mentioned volume hologram laminate and a heat seallayer formed on the volume hologram-laminated part of the volumehologram laminate and comprising a thermoplastic resin.

According to the present invention, because the volume hologram laminateexplained above is used, by arbitrary controlling the respective periodsof interference fringes formed on the volume hologram layer and theresin layer of the volume hologram laminate, it is possible to obtain avolume hologram transfer foil which can regenerate the bright hologramimage at an arbitrary wavelength.

In the volume hologram transfer foil of the present invention, areleasing layer is preferably formed between the volumehologram-laminated part and the substrate of the volume hologramlaminate. By forming the releasing layer, adhesion between the substrateand the volume hologram-laminated part can be adjusted. As a result,peelability of the volume hologram-laminated part at the time oftransferring the volume hologram-laminated part from the volume hologramtransfer foil of the present invention can be improved.

The present invention provides a volume hologram label comprising: theabove-mentioned volume hologram laminate, and a binding layer formed onthe volume hologram-laminated part of the volume hologram laminate.

According to the present invention, because the volume hologram laminateexplained above is used, by arbitrary controlling the respective periodsof interference fringes formed on the volume hologram layer and theresin layer of the volume hologram laminate, it is possible to obtain avolume hologram label to which the volume hologram that can regeneratethe bright hologram image at an arbitrary wavelength can be stuck.

Further, the volume hologram laminate of the present inventioncomprises: a resin layer partially provided on a substrate, and a volumehologram layer laminated on the substrate and formed so as to adjacentto the resin layer, characterized in that a volume hologram is formed onthe resin layer, and characterized in that a part of the volume hologramlaminate provided with the resin layer and a part of the volume hologramlaminate provided with no resin layer have different regenerated-centerwavelengths.

The volume hologram laminate of the present invention is characterizedin that the resin layer and the substrate are adjacent to each other,and that a primer layer is formed between the resin layer and thesubstrate.

The volume hologram laminate of the present invention is characterizedin that the volume hologram layer is a volume hologram layer comprisinga volume hologram recording material which contains a radicallypolymerizable monomer and a cationic polymerizable monomer, andcharacterized in that the volume hologram is formed on the resin layerby transiting the polymerizable monomer from the adjacent volumehologram recording material.

The volume hologram laminate of the present invention is characterizedin that the resin layer is made of a resin selected from the groupconsisting of a polymethyl methacrylate resin, a polyvinyl acetateresin, and a polyester resin, and characterized in that aregenerated-center wavelength of the part of the volume hologramlaminate provided with the resin layer is on a long-wavelength side whencompared to a regenerated-center wavelength of the part of the volumehologram laminate provided with no resin layer.

The volume hologram laminate of the present invention is characterizedin that the resin layer is made of a resin selected from the groupconsisting of a polyvinyl butyral resin and a polyvinyl acetal resin,and characterized in that a regenerated-center wavelength of the part ofthe volume hologram laminate provided with the resin layer is on ashort-wavelength side when compared to a regenerated-center wavelengthof the part of the volume hologram laminate provided with no resinlayer.

The volume hologram laminate of the present invention is characterizedin that a difference between the regenerated-center wavelength of thepart of the volume hologram laminate provided with the resin layer andthe regenerated-center wavelength of the part of the volume hologramlaminate provided with no resin layer is at least 10 nm or more.

A method of producing a volume hologram laminate of the presentinvention is characterized in that the following processes aresequentially carried out to a laminate obtained by partially coating andforming on a substrate a resin layer and then coating and forming on thesubstrate so as to adjacent to the resin layer a volume hologramrecording material layer comprising a radically polymerizable monomerand a cationic polymerizable monomer; (1) a process of conducting anaging treatment to the laminate and transiting the polymerizable monomerof the volume hologram recording material layer to the resin layer, (2)a hologram exposing process of exposing the laminate with laser from thesubstrate side, and (3) a hologram fixing process of conducting aheating treatment and an ultraviolet expose treatment to move thepolymerizable monomer between the resin layer and the volume hologramrecording material layer and fixing a hologram; characterized in that avolume hologram based on the polymerizable monomer transited from theadjacent volume hologram recording material layer is formed on the resinlayer; and further characterized in that regenerated-center wavelengthsof a part of the laminate provided with the resin layer and a part ofthe laminate provided with no resin layer are different.

A first volume hologram transferring sheet of the present invention ischaracterized in that an adhesive layer is provided on the volumehologram layer of the above-mentioned volume hologram laminate.

A second volume hologram transferring sheet of the present invention ischaracterized in that a second substrate is provided in a peelablemanner on the volume hologram layer of the volume hologram laminate, andan adhesive layer is provided on the resin layer and the volume hologramlayer of the volume hologram laminate where the substrate is peeledtherefrom. Alternatively, a second volume hologram transferring sheet ofthe present invention is characterized in that a second substrate isprovided in a peelable manner on the volume hologram layer of the volumehologram laminate of the present invention, and an adhesive layer isprovided on a surface of the volume hologram laminate where thesubstrate is peeled therefrom.

A volume hologram transferring sheet of the present invention ischaracterized in that the first or second volume hologram transferringsheet is a volume hologram transfer foil having its adhesive layer as aheat seal layer, or is a volume hologram transfer label having itsadhesive layer as a pressure-sensitive adhesive layer.

A volume hologram sticker of the present invention is characterized inthat the volume hologram sticker is stuck to an adherend from theadhesive layer side of the above-mentioned first volume hologramtransferring sheet, and characterized in that the substrate is peeledand removed or remains to become a protection layer of the volumehologram layer.

A volume hologram sticker of the present invention is characterized inthat the volume hologram sticker is stuck to an adherend from theadhesive layer side of the above-mentioned second volume hologramtransferring sheet, and characterized in that the second substrate ispeeled and removed or remains to become a protection layer of the volumehologram layer.

Effect of the Invention

In the method of producing a volume hologram laminate of the presentinvention, an effect of producing a volume hologram laminate in anarbitrary wavelength by a simple process can be attained. Further, thevolume hologram laminate of the present invention further attains aneffect of being able to be produced in a simple process and toregenerate a bright hologram image by controlling the regeneratedwavelength. Further in the volume hologram laminate and the volumehologram sticker of the present invention, a volume hologram which hassuch period of interference fringe that the period of interferencefringe of the volume hologram layer adjacent to the resin layerpartially provided in the layer direction is enlarged or shrunkencompare to the period of interference fringe of the volume hologramlayer provided to the part not adjacent to the resin layer in the layerdirection. Thus, the regenerated-center wavelengths can be madedifferent between the part where the resin layer is provided and thepart where no resin layer is provided in the volume hologram so that anonconventional design can be obtained. Moreover, even if a contact copyby a single wavelength laser is tried to copy the volume hologram of thepart where no resin layer is provided, by using the volume hologramlaminate of the present invention as an original master and adhering thevolume hologram recording material layer closely thereto, the part wherethe resin layer is provided and the regenerated-center wavelengththereof is different becomes dark so that copying of the volume hologramfails. Therefore, the volume hologram laminate of the present inventioncan be made to a laminate excellent in forgery prevention. In addition,the method of producing a volume hologram laminate of the presentinvention can produce a volume hologram laminate excellent in design andforgery prevention by a simple process, and further, a volume hologramsticker can be easily produced by transfer when the volume hologramtransferring sheet of the present invention is used.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A to 1E are a schematic view illustrating one embodiment of themethod of producing a volume hologram laminate of the present invention.

FIG. 2 is a graph illustrating the method to calculate the diffractionefficiency, half bandwidth and regenerated-center wavelength from thespectral transmission curve.

FIG. 3 is an electronmicrograph showing one example of a sphericaldomain which is formed on the volume hologram layer and the resin layerof the volume hologram laminate produced by the method of producing avolume hologram laminate of the present invention.

FIG. 4 is an electron micrograph showing another example of a sphericaldomain which is formed on the volume hologram layer and the resin layerof the volume hologram laminate produced by the method of producing avolume hologram laminate of the present invention.

FIG. 5 is an electron micrograph showing yet another example of aspherical domain which is formed on the volume hologram layer and theresin layer of the volume hologram laminate produced by the method ofproducing a volume hologram laminate of the present invention.

FIG. 6 is a schematic view illustrating the volume hologram laminate(first embodiment) of the present invention.

FIG. 7 is a schematic cross-section view illustrating one example of thevolume hologram transfer foil of the present invention.

FIG. 8 is a cross-section view illustrating one example of the volumehologram label of the present invention.

FIGS. 9A and 9B are each a cross-section view illustrating the volumehologram laminate (second embodiment) of the present invention.

FIG. 10 is a cross-section view illustrating the first volume hologramtransferring sheet of the present invention.

FIG. 11 is a cross-section view illustrating the volume hologram stickerproduced by using the first volume hologram transferring sheet of thepresent invention.

FIG. 12 is a cross-section view illustrating the second volume hologramtransferring sheet of the present invention.

FIG. 13 is a cross-section view illustrating the volume hologram stickerproduced by using the second volume hologram transferring sheet of thepresent invention.

FIG. 14 is a graph showing the spectral transmission curves of theExamples and the Comparative Example.

FIG. 15 is a 70%-zoomed copy of scanning electron micrograph (15,000times) of the cross section in the resin layer laminated part of thevolume hologram laminate of the present invention (second embodiment).

FIG. 16 illustrates the spectral transmission curves of the part withthe resin layer patterned and the part with no resin layer patterned ofthe volume hologram laminate of the present invention (secondembodiment).

FIG. 17 illustrates the spectral transmission curves of the part withthe resin layer patterned and the part with no resin layer patterned ofthe volume hologram laminate of the present invention (secondembodiment).

EXPLANATION OF REFERENCES

11 . . . Substrate

12 . . . Resin layer

13 . . . Volume hologram layer

110 . . . Volume hologram laminate

110′ . . . Volume hologram forming substrate

21 . . . Substrate

22 . . . Volume hologram-laminated part

22 a . . . Volume hologram layer

22 b . . . Resin layer

210 . . . Volume hologram laminate

220 . . . Volume hologram transfer foil

221 . . . Heat seal layer

230 . . . Volume hologram label

231 . . . Binding layer

1 . . . Substrate

2 . . . Resin layer

3 . . . Volume hologram layer

4 . . . Adhesive layer

5 . . . Peeling sheet

6 . . . Adherend

7 . . . Second substrate

8 . . . Primer layer

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, each embodiment of the present invention will be explainedin detail.

A. Method of Producing a Volume Hologram Laminate

First, a method of producing a volume hologram laminate of the presentinvention will be explained. As explained, the method of producing avolume hologram laminate of the present invention uses a volume hologramforming substrate which comprises: a substrate, a volume hologram layerformed on the substrate and containing a photopolymerizable material, aresin layer, framed on the substrate so as to contact to the volumehologram layer, containing a resin and a polymerizable compound,characterized in that the producing method comprises processes of: ahologram recording process to record a volume hologram to the volumehologram layer, a substance transit process of transiting thepolymerizable compound to the volume hologram layer, and anafter-treatment process of polymerizing the polymerizable compound.

Such method of producing a volume hologram laminate of the presentinvention will be explained with reference to the drawings. FIGS. 1A to1E are a schematic view illustrating the method of producing a volumehologram laminate of the present invention. As shown in FIGS. 1A to 1E,the method of producing a volume hologram laminate of the presentinvention uses a volume hologram forming substrate 110′ which comprises:a substrate 11, a resin layer 12 formed on the substrate 11 andcontaining a resin and a polymerizable compound, and a volume hologramlayer 13 formed on the resin layer 12 so as to contact to the resinlayer and containing a photopolymerizable material, (FIG. 1A),characterized in that the producing method comprises processes of: ahologram recording process to record a volume hologram to the volumehologram layer 13 (FIG. 1B), a substance transit process of transitingthe polymerizable compound contained in the resin layer 12 to the volumehologram layer 13 (FIG. 1C), and an after-treatment process ofpolymerizing the polymerizable compound transited to the volume hologramlayer 13 (FIG. 1D), and further characterized in that the methodproduces the volume hologram layer 110 which comprises at least on thesubstrate 11 the resin layer 12 and the volume hologram layer 13 havinga volume hologram recorded FIG. 1E).

According to the present invention, by using as the volume hologramforming substrate a substrate wherein the resin layer and the volumehologram layer are laminated so as to contact each other, and byrecording the volume hologram on the volume hologram layer in thehologram recording process and then transiting the polymerizablecompound from the resin layer to the volume hologram layer in thesubstance transit process, it becomes possible to change the period ofinterference fringe constituting the volume hologram afterward. Becausethe regenerated wavelength of the volume hologram coincides with theperiod of interference fringe constituting it, by transiting thepolymerizable compound into the volume hologram layer having a volumehologram recorded, it is possible to change the period of interferencefringe to the direction to enlarge the period of interference fringealready formed to the volume hologram layer. In the present invention,it is possible to enlarge the period of interference fringe to thearbitrary extent by adjusting the transiting amount of the polymerizablecompound. As such, by appropriately adjusting the wavelength of lightsused in recording the volume hologram and the transit amount of thepolymerizable compound the hologram recording process, it becomespossible to adjust the period of interference fringe afterward so thatthe volume hologram recorded to the volume hologram layer is made to thevolume hologram which can regenerate the hologram image at an arbitrarywavelength. Further, in the present invention, the period ofinterference fringe can be shorten to an arbitrary extent by selectingthe type of the resin layer.

Accordingly, in the present invention, a volume hologram laminate whichcan reproduce the hologram image in an arbitrary wavelength can beproduced by a simple process.

The method of producing a volume hologram laminate of the presentinvention comprises at least the hologram recording process, thesubstance transit process and the after-treatment process, and maycomprise other optional process as needed.

Hereinafter, each process used in the present invention will beexplained in turn.

1. Hologram Recording Process

First, a hologram recording process of the present invention will beexplained. The present process is a process to record a volume hologramto a volume hologram layer using a volume hologram forming substratewhich comprises: a substrate, a volume hologram layer formed on thesubstrate and containing a photopolymerizable material, a resin layer,formed on the substrate so as to contact to the volume hologram layer,containing a resin and a polymerizable compound.

Hereinafter, such hologram recording process will be explained indetail.

(1) Volume Hologram Forming Substrate

First, a volume hologram forming substrate used in the present processwill be explained. The volume hologram forming substrate used in thepresent process comprises at least a volume hologram layer, a resinlayer, and a substrate.

a. Resin Layer

A resin layer used in the present invention will be explained. The resinlayer used in the present invention contains at least a polymerizablecompound and a resin. In the present invention, by using such resinlayer and by transiting the polymerizable compound to the volumehologram layer in the substance transit process to be explained later,it is possible to produce a volume hologram laminate which canregenerate a hologram image in an arbitrary wavelength.

(Polymerizable Compound)

The polymerizable compound is not particularly limited as long as it canbe transited to the volume hologram layer in the substance transitprocess to be explained later. As such, the polymerizable compound usedin the present invention can be appropriately selected according tofactors such as the resin to be explained later, the composition of thevolume hologram layer, and an embodiment of the substance transitprocess. In particular, in the present invention, the polymerizablecompound is preferably a compound transited from the volume hologramlayer. Thereby, for example, it become possible to produce a volumehologram forming substrate used in the present invention by transitingthe polymerizable compound contained in the volume hologram layer afterlaminating a resin layer made of the resin only on the volume hologramlayer. Thus, the present invention can be practiced in a simpler method.Further, by making the polymerizable compound to a compound transitedfrom the volume hologram layer, transit of the polymerizable compound tothe volume hologram layer in the substance transit process to beexplained later may become easier in some cases.

Moreover, the polymerizable compound used in the present invention ispreferably a compound which cannot be polymerized by the lightirradiated to the volume hologram layer at the time of recording avolume hologram in the present process. If the polymerizable compound ispolymerized by the light used in recording the volume hologram in thepresent process, there is a risk of having difficulty in transiting thepolymerizable compound to the volume hologram layer in the substancetransit process to be explained later.

As the polymerizable compound used in the present invention, compoundssuch as a thermally polymerizable compound and a photo polymerizablecompound are cited. In the present invention, either of the compoundscan be suitably used. Further, the polymerizable compound used in thepresent invention may be a single kind or plural kinds. In particular,in the present invention, it is preferable to use a compound included inthe photopolymerizable material contained in the volume hologram layer(to be explained later) as the polymerizable compound. By using acompound same as the above-mentioned photopolymerizable materialcontained in the volume hologram layer as the polymerizable compound, itbecome easy to form a resin layer. In other words, as the volumehologram forming substrate used in the present invention has the resinlayer and the volume hologram layer laminated so as to contact eachother, for example, by transiting the photopolymerizable materialcontained in the volume hologram layer to the resin layer at the time offorming the resin layer after the formation of the volume hologramlayer, it becomes possible to easily form the resin layer containing thepolymerizable compound.

Further, when the photopolymerizable material contained in the volumehologram layer to be explained later contains a radically polymerizablecompound and a cationic polymerizable compound, the polymerizablecompound contained in the resin layer is preferably identical to thecationic polymerizable compound. The reason is as follows.

By using a radically polymerizable compound and a cationic polymerizablecompound as the photopolymerizable material in the present invention, itbecomes possible to record a volume hologram having high contrast. Inthis case, the radically polymerizable compound is to be selectivelypolymerized in the present process. Thus, by using the cationicpolymerizable compound as the polymerizable compound, polymerizablecompound is to be polymerized in the present process so that thepossibility of disturbing the transit of the polymerizable compound tothe volume hologram layer in the substance transit process to beexplained later becomes low.

The cationic polymerizable compound will be explained in detail in thesection of “b. Volume Hologram Layer” to be explained later so thatexplanation here is omitted.

An amount of the polymerizable compound contained in the resin layer isnot particularly limited as long as it is within the range which allowsthe desired amount of polymerizable compound to transit to the volumehologram layer in the substance transit process to be explained later.The specific amount contained depends on various factors such as thetype of the resin used in the resin layer, composition of the volumehologram layer and a thickness of the resin layer. In particular, in thepresent invention, it is preferably within the range of 0.1% by mass to30% by mass, more preferably within the range of 0.1% by mass to 20% bymass, and further preferably within the range of 1% by mass to 10% bymass.

(Resin)

Next, a resin used in the resin layer will be explained. The resin usedin the present invention is not particularly limited as long as it hasthe predetermined transparency. In particular, the resin used in thepresent invention preferably has a relatively large molecular weight.When the resin has a large molecular weight, it becomes easy to transitthe polymerizable compound to the volume hologram layer in the substancetransit process to be explained later. Thus, it becomes possible toshift the regenerated wavelength of the hologram images from thewavelength of the light used at the time of recording the volumehologram in the present process to a wavelength of a longer-wavelengthside. The specific molecular weight the resin used in the presentinvention is preferably within the range of 5,000 to 1,000,000, and morepreferably within the range of 5,000 to 500,000, and particularlypreferably within the range of 10,000 to 300,000.

As examples of the resin used in the present invention, the followingscan be cited: various a synthetic resin such as an acrylic-based resin,a styrene-based resin, a polyester-based resin, a urethan-based resin, apolyvinyl-based resin, a cellulose-based resin, an alkyd-based resin, apetroleum-based resin, a ketone-based resin, an epoxy-based resin, amelamine-based resin, a fluorine-based resin, a silicone-based resin,cellulose derivatives, a rubber-based resin, and a mixture thereof; athermoplastic such as a copolymer; a thermosetting such as amelamine-based resin, a phenol-based resin, a urea-based resin, anepoxy-based resin, an unsaturated polyester-based resin, a diallylphthalate-based resin, a urethan-based resin, and an amino-alkyd-basedresin; and a hardening resin typified by an ionization radiation curingresin, which is cured by the radiation of UV or electron beam, such asan acrylate-based resin, a urethane acrylate-based resin, an esteracrylate resin, and an epoxy acrylate resin.

Further, by using a polyvinyl butyral resin and a polyvinyl acetal resinfor the above-mentioned resin, it becomes possible to shift theregenerated-center wavelength to the short-wavelength side.

The resin used in the present invention may be a single kind or pluralkinds.

(Optional Compound)

The resin layer used in the present invention may contain other optionalcompound(s) other than the resin and the polymerizable compound. Theoptional compound is not particularly limited and a compound which canprovide the desired function to the resin layer according to theapplication of the volume hologram laminate produced by the presentinvention can be optionally selected. As examples of the optionalcompound, an antioxidant, a ultraviolet absorber, a light stabilizer, athermal stabilizer, a plasticizer, a lubricant, an antistat, a flameretardant and a filler can be cited. These compounds may be used aloneor in combination in the present invention.

(Resin Layer)

A thickness of the resin layer used in the present invention is notparticularly limited as long as it is within the range which allows thecontainment of the desired amount of the polymerizable compoundaccording to factors such as the type of the resin. The thicker thethickness of the resin layer is, the layer becomes possible to containlarger amount of the polymerizable compound so that it becomes possibleto transit them to the volume hologram layer. Accordingly, the thickerthe thickness of the resin layer is, the adjustment possibility of theshifted amount of the regenerated wavelength becomes wider. Therefore,it is possible to adjust the thickness of the resin layer to such extentthat the regenerated wavelength becomes within the desired range. Inparticular, in the present invention, the thickness of the resin layeris preferably within the range of 0.1 μm to 10 μm, more preferablywithin the range of 0.5 μm to 3 μm, and even more preferably within therange of 0.5 μm to 3 μm.

b. Volume Hologram Layer

A volume hologram layer used in the present invention will be explained.The volume hologram layer used in the present invention contains aphotopolymerizable material and can record a volume hologram because theinterference fringe will be formed in the hologram recording process tobe explained later.

Hereinafter, such volume hologram layer will be explained in detail.

(Photopolymerizable Material)

First, a photopolymerizable material used in the present invention willbe explained. The photopolymerizable material used in the presentinvention is not particularly limited as long as the material canprogress the polymerization reaction by being irradiated with thepredetermined light and can form the interference fringe to the volumehologram layer. In particular, in the present invention, it ispreferable to use at least one of the radically polymerizable compoundor cationic polymerizable compound. From the view point to enabling therecording of a hologram image with high contrast, it is particularlypreferable to combine the radically polymerizable compound and thecationic polymerizable compound.

Further, when the radically polymerizable compound is used as thephotopolymerizable material, the photo radical polymerization initiatoris preferably used in order to start the polymerization reaction of theradically polymerizable compound. In contrast, when the cationicpolymerizable compound is used as the photopolymerizable material, thephoto cationic polymerization initiator is preferably used because ofthe similar reason to the above.

In addition, when the radically polymerizable compound and the cationicpolymerizable compound are used as the photopolymerizable material, thephoto radical polymerization initiator and the photo cationicpolymerization initiator is preferably used.

Since the volume hologram layer of the volume hologram forming substrateis a state before the recording of the volume hologram, thephotopolymerizable material is presented in the volume hologram layer inan unpolymerized state.

Hereinafter, the radically polymerizable compound, the cationicpolymerizable compound, the photo radical polymerization initiator, andthe photo cationic polymerization initiator used in the presentinvention will be explained in turn.

First, the cationic polymerizable compound used in the present inventionwill be explained. The cationic polymerizable compound used in thepresent invention is a compound which cationic-polymerizes, when beingirradiated with energy, by a Brønsted acid or a Lewis acid generatedthrough the decomposition of the photo cationic polymerization initiatorto be explained later.

When the radically polymerizable compound and the cationic polymerizablecompound is used as the photopolymerizable material, the recording ofvolume hologram in the present process is generally carried out byirradiating the energy to the entire surface and to polymerize theuncured substance such as the cationic polymerizable compound, after theradically polymerizable compound is polymerized at the part having alarge light intensity in the interference fringe at the time ofinterference exposure. At this time, the laser used in forming thehologram image and the energy irradiated to the entire surface havegenerally different wavelengths. Thus, the cationic polymerizablecompound used in the present invention is preferably a compound whichdoes not polymerize at the wavelength of the light source used informing the hologram image.

Further, from the view point that the polymerization of the radicallypolymerizable compound is preferably conducted in the composition havinga relatively low viscosity, the cationic polymerizable compound used inthe present invention is preferably in a liquid form at roomtemperature.

As examples of such cationic polymerizable compound, compounds describedin the following references can be cited: Chemtec. October, J. V.Crivello, page 624 (1980) ; JP-A NO. 62-149784; Journal of the AdhesionSociety of Japan (Vol. 26, No. 5, pages 179-187 (1990)); JP-A NO.5-107999; JP-A NO. 2002-236439; and JP-A NO. 2002-236440.

In the present invention, each of the cationic polymerizable compoundscan be suitable use. In particular, a cationic polymerizable compoundhaving three or more polymerization functional group per one molecule ispreferable. Thereby, a crosslink density in the volume hologram layercan be made higher and the foil cuttability of the volume hologram layeris made excellent.

The cationic polymerizable compound used in the present invention may beof a single kind or be two or more kinds.

Next, the radically polymerizable compound used in the present inventionwill be explained. The radically polymerizable compound used in thepresent invention is not particularly limited as long as it is acompound which polymerizes by the action of the active radical generatedfrom the photo radical polymerization initiator to be explained later,at the time of forming the volume hologram layer through, for example,laser irradiation. In the present invention, a compound having at leastone ethylenic unsaturated double bond in a molecule is preferable.

Here, the volume hologram layer is a layer which forms the interferencefringe and forms a hologram image by polymerizing the radicallypolymerizable compound with a light such as a laser light or a lighthaving excellent coherence. Thus, for the radically polymerizablecompound and the cationic polymerizable compound, compounds havingdifferent refractive indexes are generally selected. The magnituderelation in the refractive indexes between the radically polymerizablecompound and the cationic polymerizable compound used in the presentinvention is not particularly limited. However, in particular, theaverage refractive index of the radically polymerizable compound ispreferably larger than that of the cationic polymerizable compound fromthe view point of material selectivity. Specifically, the difference inthe average refractive index is preferably 0.02 or larger. This isbecause, when the difference in the average refractive indexes betweenthe radically polymerizable compound and the cationic polymerizablecompound is smaller than the above-mentioned value, refractive-indexmodulation becomes insufficient and it may become difficult to form ahighly precise hologram image.

The average refractive index mentioned here denotes the average value ofthe refractive indexes obtained by measuring polymers obtained throughpolymerizing the cationic polymerizable compound or the radicallypolymerizable compound polymerization. Moreover, the average refractiveindex mentioned in the present invention denotes the vale measured bythe abbe refractometer.

As examples of the radically polymerizable compound used in the presentinvention, compounds described in the following references can be cited:JP-A NO. 5-107999, JP-A NO. 2002-236439, and JP-A No. 2002-236440.Further, the radically polymerizable compound in the present inventionmay be of a single kind or be a mixture of two or more kinds.

Next, the photo radical polymerization initiator used in the presentinvention will be explained. The photo radical polymerization initiatorused in the present invention is not particularly limited as long as itis an initiator which can polymerize the radically polymerizablecompound by generating the active radical through the irradiated lightat the time of forming the volume hologram to the volume hologram layerin the present process. As examples of such photo radical polymerizationinitiator, an initiator described in the following references can becited: U.S. Pat. Nos. 4,766,055, 4,868,092, 4,965,171, JP-A No.54-151024, JP-A No. 58-15503, JP-A No. 58-29803, JP-A No. 59-189340,JP-A No. 60-76735, JP-A No. 1-28715, Japanese Patent Application NO.3-5569, and “PROCEEDINGS OF CONFERENCE ON RADIATION CURING ASIA (Pages461-477, 1988)”.

Next, the photo cationic polymerization initiator used in the presentinvention will be explained. The photo cationic polymerization initiatorused in the present invention is not particularly limited as long as itis a compound which can polymerize the cationic polymerizable compoundby generating a Brønsted acid or a Lewis acid by the irradiated energy.In particular, in the present invention, the radically polymerizablecompound is preferably a compound which does not react with a light suchas a laser light or a light having excellent coherence and is low inphotosensitivity which photosensitizes to the energy irradiated to theentire surface afterwards. Thereby, the cationic polymerizable compoundcan remain with almost no reaction at the time of polymerizing theradically polymerizable compound so that a large refractive-indexmodulation is obtained in the volume hologram layer.

The photo cationic polymerization initiator low in photosensitivity to alight such as a laser light or a light having excellent coherencedenotes an agent which shows maximum value 500 mW or lower (including 0mW) per 1 mg measurement sample in the DSC value which results from aphotopolymerization initiated by the photo cationic polymerizationinitiator when the heat analysis is conducted under the followingconditions.

(Measuring Conditions)

Measuring Device: differential scanning calorimeter DSC 220 and lightsourcing device UV-1 are used in heat analysis system SSC5200Hmanufactured by Seiko Instruments Inc.

Measurement Sample: prepared by dissolving the subjected-photo cationicpolymerization initiator 3% by mass into UVR-6110 (cationicpolymerizable compound) manufactured by Union Carbide Corporation (mayalso be prepared by adding, dissolving and evaporating an organicsolvent).

Irradiating light: irradiate a light adjusted to the laser light or alight having excellent coherence using an interference filter (halfbandwidth about 10 nm) by 200 mJ/cm².

As examples of such photo cationic polymerization initiator, aninitiator described in the following references can be cited: “UVCuring: Science and Technology”, pages 23-76, edited by S. PeterPappas,A Technology Marketing Publication; “Comments Inorg. Chem.”, B.Klingert, M. Riediker and A. Roloff, Vol. 7, No. 3, pages 109-138(1988); JP-A No. 5-107999, JP-A No. 2002-236439 and JP-A No.2002-236440. Further, in the present invention, one or plural kinds ofthe above can be used.

(Optional Compound)

The volume hologram layer used in the present invention may containother optional compounds) other than the photopolymerizable materialmentioned above. The optional compound used in the present invention isnot particularly limited as long as the compound can provide the desiredfunction to the volume hologram layer according to factors such as anapplication of the volume hologram laminate produced by the presentinvention. As examples of such optional compound, a sensitizing dye,fine particles, an anti-heat polymerization agent, a silane couplingagent, a plasticizer, a coloring agent, and a polymer bonding agent canbe cited. In particular, in the present invention, a binder resin, fineparticles and a sensitizing dye is preferably used. This is because, byusing a binder resin, it is possible to obtain a uniform the volumehologram layer and maintain hologram image formed by the polymerizationof the radically polymerizable compound.

Further, by using fine particles, it is possible to provide the desiredfoil cuttability to the volume hologram layer.

In addition, many of the photopolymerizable materials are active to theUV. By using a sensitizing dye, the materials become also active to thevisible light and thereby it becomes possible to record the volumehologram using the visible laser.

As examples of the binder resin, poly(meth)acrylic acid ester or apartial hydrolysate thereof, polyvinyl acetate or a hydrolysate thereof,polyvinyl alcohol or a partial acetal compound thereof, triacetylcellulose, polyisoprene, polybutadiene, polychloroprene, siliconerubber, polystyrene, polyvinyl butyral, polyvinyl chloride, polyarylate,chlorinated polyethylene, chlorinated polypropylene, poly-N-vinylcarbazole or a derivative thereof, poly-N-vinylpyrrolidone or aderivative thereof and a copolymer of styrene and maleic acid anhydrideor a half ester thereof. Further, a copolymer obtained by polymerizingat least one monomer selected from the group consisting of acrylic acid,acrylic acid ester, methacrylic acid, methacrylic acid ester,acrylamide, acrylonitrile, ethylene, propylene, chloroethene and vinylacetate. Moreover, in the present invention, a single kind or a mixtureof plural kinds of these binder resins may be used alone.

In addition, a hardening resin of oligomer type may be used as thebinder resin. As examples of the resin, an epoxy compound generatedthrough a condensation reaction of various phenol compounds such asbisphenol A, bisphenol S, novolac, o-cresolnovolac, andp-alkylphenolnovolac, and Epichlorohydrin can be cited.

(Volume Hologram Layer)

The volume hologram layer used in the present invention preferably has aglass-transition point of 100° C. or higher. Thereby, the volumehologram layer becomes stable even when a heat is applied to the layer,and it becomes possible to transfer the volume hologram layer by amethod such as a heat transfer method.

A thickness of the volume hologram layer used in the present inventionis not particularly limited as long as the desired hologram image can beobtained. Normally, the thickness is preferably within the range of 1 μmto 50 μm, more preferably within the range of 3 μm to 40 μm, and evenmore preferably within the range of 5 μm to 30 μm.

c. Substrate

Next, a substrate used in the present invention will be explained. Thesubstrate used in the present invention has a function to support theabove-mentioned resin layer and volume hologram layer.

The substrate used in the present invention is not particularly limitedas long as it can support the resin layer and volume hologram layer. Forexample, a common polyester film such as a polyethylene terephthalatefilm can be used as the substrate.

Further, a thickness of the substrate used in the present invention isappropriately selected according to factors such as an application andkind of the volume hologram laminate produced in the present invention.Generally, the thickness is within the range of 2 μm to 200 μm, and ispreferably within the range of 10 μm to 50 μm.

When the adhesion between the substrate and the resin layer or thevolume hologram layer used in the present invention is insufficient, theadhesion can be improved by between the substrate and the resin layer orthe volume hologram layer by conducting a surface treatment such as acorona treatment, an ozonation treatment, a plasma treatment, anionization radiation treatment, a bichromatic treatment, an anchoring orprimer treatment to the substrate surface. As the primer, various primeragent such as urethane-based, acrylic-based, ethylene-vinyl acetatecopolymer-based, and chloroethene-vinyl acetate copolymer-based areknown. A suitable for the substrate can be selected from the above.

d. Volume Hologram Forming Substrate

A volume hologram forming substrate used in the present processcomprises the above-mentioned substrate, resin layer and volume hologramlayer. An embodiment wherein these members are formed is notparticularly limited as long as it is an embodiment wherein the resinlayer and the volume hologram layer are laminated so as to contact eachother. Thus, the volume hologram forming substrate used in the presentinvention may have an embodiment wherein the resin layer and the volumehologram layer are laminated on the substrate in this order, or may havean embodiment wherein the volume hologram layer and the resin layer arelaminated on the substrate in this order. The embodiment of the volumehologram forming substrate used in the present invention isappropriately selected from factors such as a method employed inrecording the volume hologram in the hologram recording process to beexplained later. For example, when a method of recording the volumehologram using the hologram original master in the hologram recordingprocess is employed, it is desired to provide the hologram originalmaster close to the volume hologram layer. Accordingly, an embodiment ofvolume hologram forming substrate used in the present invention ispreferably the one wherein the resin layer and the volume hologram layerare laminated on the substrate in this order.

The volume hologram forming substrate used in the present inventioncomprises at least the resin layer, the volume hologram layer, and thesubstrate, but it may have an optional technical structure as needed.The optional technical structure used in the present invention is notparticularly limited, and a technical structure having the desiredfunction according to an application of the volume hologram laminateproduced in the present invention may be used. As examples of suchtechnical structure, a hard coat layer, a static charge preventionlayer, a printing layer, an ink-receiving layer and a releasing layercan be cited.

e. Producing Method of Volume Hologram Forming Substrate

Next, a method of producing the volume hologram forming substrate usedin the present invention will be explained. The volume hologram formingsubstrate used in the present invention can be produced by a methodwherein the resin layer and the volume hologram layer are separatelyformed on the substrate in this order. However, the following methodsare preferable because they can produce the substrate in a simplerproducing process: a method, wherein a resin layer containing nopolymerizable compound is formed on a substrate, then a volume hologramlayer is formed on the resin layer and further, a part of aphotopolymerizable material contained in the volume hologram layer istransited to the resin layer; or a method, wherein a volume hologramlayer is formed on a substrate, then a resin layer containing nopolymerizable compound is formed on the volume hologram layer, andfurther, a part of a photopolymerizable material contained in the volumehologram layer is transited to the resin layer.

Hereinafter, these methods will be explained as examples of the methodto produce a volume hologram forming substrate used in the presentinvention.

First, a method of forming the resin layer containing no polymerizablecompound on the substrate will be explained. In the method of formingthe resin layer containing no polymerizable compound on the substrate, acommon method of forming a layer made of a resin material can be used.For example, a method of coating a molten material of a resin or acoating solution prepared by dissolving a resin into a solvent on thesubstrate, and a method of attaching a film made of a resin to thesubstrate, can be cited. In the present invention, either of method canbe suitably used according to the type of the resin used in the resinlayer.

Next, a method of forming the volume hologram layer on the resin layerwill be explained. As a method of forming the volume hologram layer onthe resin layer, for example, a method of coating a solution prepared bydissolving a photopolymerizable material on the resin layer, and amethod of attaching a film containing a photopolymerizable material tothe resin layer, can be cited.

Next, a method of transiting the photopolymerizable material containedin the volume hologram layer to the resin layer will be explained. Asthe resin layer and the volume hologram layer are formed in a mannerthey contact each other, it is generally possible to transit thephotopolymerizable material to the resin layer under the principle ofequilibrium shift by heating the resin layer and the volume hologramlayer together. At this time, it is possible to arbitrary adjust thetransit amount of the photopolymerizable material by controlling theheating time and heating temperature.

When the method of coating a solution having the photopolymerizablematerial dissolved therein is used as the method of forming the volumehologram layer on the resin layer, a separate process such as heatingprocess as explained above may not be needed in some cases, because itis possible to transit the photopolymerizable material to the resinlayer due to the penetration of the solution to the resin layer causedwhen the solution is coated on the resin layer.

Further, when the method, wherein a volume hologram layer is formed on asubstrate, then a resin layer containing no polymerizable compound isformed on the volume hologram layer, and further, a part of aphotopolymerizable material contained in the volume hologram layer istransited to the resin layer, is used, a volume hologram formingsubstrate can be produced by the above-mentioned method other thanreversing the forming order of the resin layer and the volume hologram.

(2) Volume Hologram Recording Process

Next, a method of recording the volume hologram to the volume hologramlayer provided to the above-mentioned volume hologram forming substratewill be explained.

The volume hologram is to record a hologram image by fixing theinterference fringe generated by light interference to the volumehologram layer containing the photopolymerizable material as a fringehaving different refractive indexes. Accordingly, the method ofrecording the volume hologram in the present process is not particularlylimited as long as it is a method which allows the recording of thepredetermined interference fringe to the volume hologram layer. Asexamples of such method, the following methods can be cited: a method ofinjecting a reference light beam from the substrate side of the volumehologram forming substrate, injecting an object light beam from thevolume hologram layer side and making these lights interfere in thevolume hologram layer; and a method of providing a hologram originalmaster on the volume hologram layer, and making the injected light andthe reflected light reflected by the hologram original master interferein the volume hologram layer by injecting the light from the substrateside. Either method can be used suitably in the present process. Inparticular, the method of using the above-mentioned hologram originalmaster is preferable. This is because, such a method allows a simple andeasy recording of the volume hologram.

When the above-mentioned method of using the hologram original master isemployed in the present process, a substrate having the resin layer andthe volume hologram layer laminated in this order on the substrate isused as the volume hologram forming substrate for the present process.

When a photopolymerizable material containing a single photopolymerizable compound is used as the photopolymerizable material forthe volume hologram layer, the volume hologram is to be recorded bypolymerizing the photo polymerizable compound in the present process.However, when a photopolymerizable material containing plural photopolymerizable compounds is used as the photopolymerizable material, itis sufficient to polymerize at least one photo polymerizable compound inorder to record the volume hologram in the present process.

When the material containing the above-mentioned radically polymerizablecompound and cationic polymerizable compound is used as thephotopolymerizable material, the volume hologram is generally recordedby polymerizing the radically polymerizable compound in the presentprocess.

2. Substance Transit Process

Next, substance transit process of the present invention will beexplained. The present process is a process to transit the polymerizablecompound contained in the resin layer to the volume hologram layerhaving a volume hologram recorded in the hologram recording process.Further, the present process can also be regarded as a process ofarbitrary enlarging the period of interference fringe recorded to thevolume hologram layer by transiting the polymerizable compound from theresin layer to the volume hologram layer, and thereby enabling theregeneration of the volume hologram recorded to the volume hologramlayer at an arbitrary wavelength.

In present process, the method of transiting the polymerizable compoundfrom the resin layer to the volume hologram layer is not particularlylimited as long as it is a method which transits the desired amount ofpolymerizable compound and to make the period of interference fringerecorded to the volume hologram layer within the predetermined range. Asexamples of such method, the following can be cited: a method to leavethe resin layer and the volume hologram layer in contacting state forthe predetermined time, and a method of heating the resin layer and thevolume hologram layer together. Either of the methods can be suitablyused in the present process, however, the method of heating the resinlayer and the volume hologram layer together is preferable. This isbecause, such method allows arbitrary adjustment of the transitingamount of the polymerizable compound by controlling factors such as theheating time and heating temperature.

3. After-Treatment Process

Next, the after-treatment process of the present invention will beexplained. The present process is a process of polymerizing theabove-mentioned polymerizable compound.

A method of polymerizing the polymerizable compound is appropriatelyselected according to the type of the polymerizable compound. In otherwords, when the polymerizable compound is a photo polymerizablecompound, a method of irradiating a light which can induce thepolymerization reaction according to the kind of the photopolymerizationfunctional group of the photo polymerizable compound is employed. Whenthe polymerizable compound is a thermally polymerizable compound, aheating treatment method which can induce the polymerization reaction ofthe thermal polymerization functional group of the thermallypolymerizable compound will be employed.

Here, since the polymerizable compound is transited to the volumehologram layer in the above-mentioned substance transit process, thepolymerizable compounds are contained in both of the resin layer and thevolume hologram layer at the time of the present process. Accordingly,in the present process, the polymerizable compounds contained in theresin layer and the volume hologram layer are generally simultaneouslypolymerized.

The polymerizable compound contained in the resin layer and the volumehologram layer is not to be transited after this process because it isfixed by the polymerization of the present process. Thus, theregenerated wavelength of the volume hologram is to be fixed in thepresent process.

4. Volume Hologram Laminate

Next, a volume hologram laminate produced in the pre sent invention willbe explained. As the volume hologram laminate produced in the presentinvention uses the above-mentioned volume hologram forming substrate,the volume hologram laminate produced in the present invention comprisesthe substrate, the resin layer formed on the substrate, and the volumehologram layer framed on the substrate so as to contact to the resinlayer.

Further, since the volume hologram laminate produced in the presentinvention is a laminate wherein the volume hologram is recorded to thevolume hologram layer, the volume hologram layer has at least theinterference fringe recorded, but the resin layer may also have theinterference fringe recorded depending on the kind of the polymerizablecompound contained in the resin layer. At this time, when the period ofinterference fringe formed to the volume hologram layer and the periodof interference fringe formed to the resin layer are different, thehologram image can be regenerated at plural wavelengths. Thus, it ispossible to obtain a volume hologram laminate which can regenerate abright hologram image.

Here, the volume hologram laminate produced in the present invention isto have features resulting from the fact that it is produced by theproducing method of a volume hologram explained in the presentinvention. That is, the volume hologram laminate produced in the presentinvention has a feature that a spherical domain is produced in at leastone of the volume hologram layer and the resin layer.

The spherical domain formed on the volume hologram layer and the resinlayer of the volume hologram laminate produced by the present inventionwill be specifically explained by showing examples. FIGS. 3 to 5 areeach an electron micrograph showing an example of a spherical domainformed on the volume hologram layer and the resin layer of the volumehologram laminate produced by the method of producing a volume hologramlaminate of the present invention. As respectively shown in FIGS. 3 to5, the volume hologram laminate produced by the present invention is alaminate where a spherical domain is formed on the volume hologram layerand the resin layer.

As shown, the volume hologram laminate produced by the present inventionis characterized in that a spherical domain is formed on the volumehologram layer and the resin layer, whether a given volume hologramlaminate is produced by the producing method of the present inventioncan be easily judged by the presence of the above-mentioned sphericaldomain. The presence of the spherical domain can be clearly confirmed byobserving the cross-sections of the volume hologram layer and the resinlayer under the transmission electron microscope.

B. Volume Hologram Laminate (First embodiment)

Next, the volume hologram laminate of the first embodiment of thepresent invention will be explained.

The volume hologram laminate of the present invention comprises: asubstrate, a volume hologram layer formed on the substrate andcontaining a photopolymerizable compound, in which a volume hologram isrecorded by forming an interference fringe, and a volumehologram-laminated part formed so as to contact to the volume hologramlayer and comprising a resin layer which contains a transparent resin,characterized in that an interference fringe is formed on the resinlayer.

The volume hologram laminate of the present invention will be explainedwith reference to the drawings. FIG. 6 is a schematic view illustratingthe volume hologram laminate of the present invention. As shown in FIG.6, volume hologram laminate 210 of the present invention volume hologramlaminate comprises: a substrate 21, a volume hologram layer 22 a fannedon the substrate 21, and a volume hologram-laminated part 22 formed soas to contact to the volume hologram layer 22 a and comprising a resinlayer 22 b which contains a transparent resin. Here, the volume hologramlayer 22 a contains the photo polymerizable compound and is a layerhaving the volume hologram recorded by forming the interference fringe.In such an embodiment, the volume hologram laminate 210 of the presentinvention is characterized in that the interference fringe is formed tothe resin layer 22 b. In other words, the volume hologram laminate 210of the present invention is characterized in that the interferencefringes are formed to both of the volume hologram layer 22 a and theresin layer 22 b.

Here, the embodiment for the volume hologram laminate of the presentinvention wherein the volume hologram layer and the resin layer arelaminated on the substrate in this order is explained. However, thevolume hologram laminate of the present invention is not limited to thistechnical structure. The volume hologram laminate of the presentinvention may have a technical structure wherein a resin layer and thevolume hologram layer are laminated on the substrate in this order.

According to the present invention, because the interference fringe isalso formed on the resin layer, by arbitrary controlling the respectiveperiods of interference fringes formed on the volume hologram layer andthe resin layer, it is possible to obtain a volume hologram laminatewhich can regenerate the bright hologram image at an arbitrarywavelength. Further, because the resin layer is formed so as to contactto the volume hologram layer in the present invention, the volumehologram laminate of the present invention can be produced by, forexample, a method of simultaneously recording the interference fringesto the resin layer and the volume hologram layer after the volumehologram layer is directly formed on the resin layer. Accordingly, avolume hologram laminate which can be produced in a simple method isobtained in the present invention. Thus, according to the presentinvention, it is possible to provide a volume hologram laminate whichcan be produced in a simple process and which can regenerate a brighthologram image by controlling the regenerated wavelength.

The volume hologram laminate of the present invention comprises at leastthe substrate and the volume hologram-laminated part and may compriseother technical structure as needed. Hereinafter, each technicalstructures of the present invention will be explained in turn.

1. Volume Hologram-Laminated Part

First, a volume hologram laminated part used in the present inventionwill be explained. The volume hologram laminated part used in thepresent invention is formed by laminating the volume hologram layerwhere the volume hologram is recorded and the resin layer containing thetransparent resin as such that they contact each other.

1-1: Resin Layer

First, a resin layer used in the present invention will be explained.The resin layer used in the present invention contains a transparentresin and has an interference fringe formed. Hereinafter, such resinlayer will be explained.

(1) Interference Fringe

As explained, the resin layer of the present invention has theinterference fringe formed, but the period of interference fringe formedon the resin layer is not particularly restricted and can be arbitrarydecided according to factors such as the period of interference fringeformed on the volume hologram layer to be explained later.

Here, the formation of the interference fringe in the resin layer usedin the present invention can be confirmed by observing a section,obtained by cutting the resin layer to the thickness direction, under atransmission electron microscope (TEM).

Further, the “period of interference fringe” used in the presentinvention denotes a distance between the adjacent bright fringes orbetween adjacent dark fringes. The period of interference fringe can beobtained by calculating it from the interference fringe of thecross-section photographed by the transmission electron microscope (TEM)based on TEM diameter, while also by measuring the wavelength dependencyof the transmission of the resin layer. That is, since the light havingthe wavelength which satisfies the bragg conditions obtained by theperiod of interference fringe among the light injected from a certaindirection to the resin layer is to be diffracted in the resin layer, thewavelength dependency of the transmission of the resin layer shows theminimal value at the wavelength which satisfies the bragg conditions.Accordingly, it is possible to obtain the period of interference fringeby obtaining the minimum transmitted-wavelength in the wavelengthdependency of the transmission. In the method of obtaining the periodusing the transmission electron microscope, the period of interferencefringe of the resin layer is typified by the average period of the partswhose periodic fringes are clearly photographed out of photographedinterference fringes.

The periods of interference fringe formed to the resin layer used in thepresent invention may be constant or different. When the interferencefringes have plural different periods, the embodiment of forminginterference fringes having different periods may be an embodimentwherein the period of interference fringes formed in a successivelychanging manner, or may be an embodiment wherein the interferencefringes having different periods are formed in an intermittent manner.

Further, the period of interference fringe formed on the resin layerused in the present invention may be identical to or different from theperiod of interference fringe formed on the volume hologram layer to beexplained later. In particular, in the present invention, the period ofinterference fringe formed on the resin layer used in the presentinvention is preferably different from the period of interference fringeformed on the volume hologram layer to be explained layer. Thereby,because the hologram image can be regenerated at a wavelength whichcoincides with one of the periods of interference fringes formed on theresin layer and the volume hologram layer, it becomes possible toregenerate the hologram image at plural regenerated wavelengths so thatthe volume hologram laminate of the present invention can be made to thelaminate which can regenerate brighter hologram image.

When the period of interference fringe formed on the resin layer isdifferent from the period of interference fringe formed on the volumehologram layer to be explained later, the period of interference fringeformed on the resin layer may be bigger or smaller than the period ofinterference fringe formed on the volume hologram layer.

Here, in the present invention, the period of interference fringe formedon the resin layer is “different” from the period of interference fringeformed on the volume hologram layer (to be explained later) denotes thatthere is at least 3 nm or more difference between the periods ofinterference fringes for both layers.

(2) Transparent Resin

Next, the transparent resin will be explained. The transparent resinused in the present invention is not particularly limited as long as ithas the predetermined transparency. Here, the transparent resin used inthe present invention is the same as that explained in theabove-mentioned section of “A. Method of Producing Volume HologramLaminate”, explanation here is omitted.

(3) Optional Compound

In the resin layer used in the present invention, optional compound(s)may be included arbitrary other than the transparent resin. The optionalcompound is not particularly limited and one which can provide thedesired function(s) to the resin layer can be arbitrary selectedaccording to the application of the volume hologram laminate of thepresent invention. Here, the optional compound is the same as thatexplained in the above-mentioned section of “A. Method of ProducingVolume Hologram Laminate”, explanation here is omitted.

(4) Resin Layer

A thickness of the resin layer used in the present invention is notparticularly limited as long as it can make the volume hologram laminateof the present invention to a laminate which can regenerate a hologramimage at the desired wavelength according to the factors such as thekind of the transparent resin.

1-2: Volume Hologram Layer

Next, a volume hologram layer used in the present invention will beexplained. The volume hologram layer used in the present inventioncontains a photo polymerizable compound, in which the volume hologram isrecorded by forming an interference fringe.

Hereinafter, such volume hologram layer will be explained.

(1) Interference Fringe

As explained above, the volume hologram layer used in the presentinvention has an interference fringe formed. The periods of interferencefringes formed to the volume hologram layer may be constant ordifferent. When the interference fringes have plural different periods,the embodiment of forming interference fringes having different periodsmay be an embodiment wherein the period of interference fringes areformed in a successively changing manner or may be an embodiment whereinthe interference fringes having different periods are formed in anintermittent manner.

The period of interference fringe formed on the volume hologram layerused in the present invention may be identical to or different from theperiod of interference fringe formed on the resin layer explained above.In particular, in the present invention, the above-mentioned period ofinterference fringe formed on the resin layer is preferably differentfrom the period of interference fringe formed on the volume hologramlayer. Thereby, because the hologram image can be regenerated at awavelength which coincides with one of the periods of interferencefringes formed on the resin layer and the volume hologram layer, itbecomes possible to regenerate the hologram image at plural regeneratedwavelengths so that the volume hologram laminate of the presentinvention can be made to the laminate which can regenerate brighterhologram image. The embodiment wherein the period of interference fringeformed on the above-mentioned resin layer is different from the periodof interference fringe formed on the volume hologram layer is explainedin the above-mentioned section of “1-1. Resin Layer” as the embodimentof the interference fringe formed on the resin layer. Thus explanationhere is omitted.

The specific period of the interference fringes formed to the volumehologram layer used in the present invention is equivalent to thewavelength of visible light range.

(2) Photo Polymerizable Compound

Next, the photo polymerizable compound contained in the volume hologramlayer will be explained. The photo polymerizable compound contained inthe volume hologram layer is not particularly limited as long as it canprogress the polymerization reaction by being irradiated with thepredetermined light and can form the interference fringe to the volumehologram layer. The photo polymerizable compound contained in the volumehologram layer is identical to those explained in the above-mentionedsection of “A. Producing Method of Volume Hologram Laminate”, thusexplanation here is omitted.

Since the volume hologram layer of the present invention is the layerhaving the recorded-volume hologram, the photo polymerizable compound isto be contained in the volume hologram layer as a polymerized product.

(3) Optional Compound

The volume hologram layer used in the present invention may containother optional compound(s) other than the above-mentioned photopolymerizable compound. The optional compound used in the presentinvention can be appropriately selected according to factors such as anapplication of the volume hologram laminate of the present invention. Asthe optional compound used in the volume hologram layer of the presentinvention is identical to those explained in the above-mentioned section“A. Producing Method of Volume Hologram Laminate”, explanation here isomitted.

1-3. Volume Hologram-Laminated Part

A volume hologram-laminated part used in the present invention is formedon the substrate to be explained later. An embodiment wherein the volumehologram-laminated part used in the present invention is formed on thesubstrate may be: an embodiment wherein the volume hologram layer sideis formed so as to be provided to the substrate side; or an embodimentwherein the resin layer side is formed so as to be provided thesubstrate side.

2. Substrate

Next, a substrate used in the present invention will be explained. Thesubstrate used in the present invention has a function to support theabove-mentioned volume hologram-laminated part. As the substrate used inthe present invention is identical to those explained in theabove-mentioned section of “A. Producing Method of Volume HologramLaminate”, explanation here is omitted.

3. Optional Technical Structure

The volume hologram laminate of the present invention comprises at leastthe volume hologram-laminated part and the substrate, it may also hasother optional technical structure as needed. The optional technicalstructure used in the present invention is not particularly limited anda structure which has the desired function according to an applicationof the volume hologram laminate of the present invention may be used.

4. Volume Hologram Laminate

A volume hologram laminate of the present invention preferably shows atleast 2 minimal transparent wavelengths in the transmittance in visiblelight range. Thereby, the volume hologram laminate of the presentinvention becomes a laminate which can reproduce a further brighthologram image.

C. Volume Hologram Transfer Foil

Next, a volume hologram transfer foil of the present invention will beexplained. As explained above, the volume hologram transfer foil of thepresent invention comprises the volume hologram laminate of the presentinvention, and a heat seal layer formed on the volume hologram-laminatedpart of the volume hologram laminate and comprising a thermoplasticresin.

The volume hologram transfer foil of the present invention will beexplained with reference to the drawings. FIG. 7 is a schematiccross-section view illustrating one example of the volume hologramtransfer foil of the present invention. As shown in FIG. 7, a volumehologram transfer foil 220 of the present invention comprises: theabove-mentioned volume hologram laminate 210, and a heat seal layer 221formed on the volume hologram-laminated part 22 of the volume hologramlaminate 210 and comprises a thermoplastic resin.

According to the present invention, because the volume hologram laminateis used, by arbitrary controlling the respective periods of interferencefringes formed on the volume hologram layer and the resin layer of thevolume hologram laminate, it is possible to obtain a volume hologramtransfer foil to which the volume hologram that can regenerate thebright hologram image at an arbitrary wavelength can be transferred.

The volume hologram transfer foil of the present invention comprises atleast the volume hologram laminate and the heat seal layer.

Hereinafter, the respective technical structure used in the volumehologram transfer foil will be explained in turn.

1. Volume Hologram Laminate

First, a volume hologram laminate used in the present invention will beexplained. The volume hologram laminate used in the present inventionrelates to the above-mentioned embodiment. Thus, the volume hologramlaminate used in the present invention is the same to the one explainedin the above-mentioned section of “B. Volume Hologram Laminate”.

Here, as explained above, the volume hologram laminate used in thepresent invention comprises at least the substrate and the volumehologram-laminated part. However, in view of that the volume hologramlaminate of the present invention will be used in the volume hologramtransfer foil, the volume hologram laminate of the present inventionpreferably has other technical structure than the above. As examples ofthe other technical structure for the volume hologram laminate, areleasing layer and a protection layer can be cited.

2. Heat Seal Layer

Next, a heat seal layer used in the present invention will be explained.The heat seal layer used in the present invention comprises athermoplastic resin, and has a function to adhere the volumehologram-laminated part and a member to be transferred, at the time oftransferring the volume hologram-laminated part to the member to betransferred using the volume hologram transfer foil of the presentinvention. Hereinafter, the heat seal layer used in the presentinvention will be explained in detail.

The thermoplastic resin used in the present invention is notparticularly limited as long as it is a resin which can adhere thevolume hologram-laminated part and a member to be transferred accordingto the kind of the member to which the volume hologram-laminated part istransferred from the volume hologram transfer foil of the presentinvention. As specific examples are identical to those to be explainedlater in the section of “E. Volume Hologram Laminate (SecondEmbodiment)”, explanation here is omitted.

The thermoplastic resin used in the present invention may be a singlekind or plural kinds.

The heat seal layer used in the present invention may further containother additive(s) in addition to the thermoplastic resin. As theexamples of other additive(s) used in the present invention, adispersant, a filler, a plasticizer, and an antistat can be cited.

A thickness of the heat seal layer used in the present invention is notparticularly limited and appropriately selected according to factorssuch as the kind of a member to be transferred, to which the volumehologram-laminated part is transferred using the volume hologramtransfer foil of the present invention. In general, the thickness ispreferably within the scope of 0.3 μm to 50 μm, and more preferablywithin the scope of 0.5 μm to 25 μm. When the thickness is thinner thanthe above-mentioned range, there is a possibility of the adhesion to themember to be transferred may become insufficient. When the thickness isthicker than the above-mentioned range, a temperature to heat the heatseal layer becomes too high at time of transferring the volumehologram-laminated part from the volume hologram transfer foil of thepresent invention and there is a possibility of damaging the othermember such as the substrate.

Further, the heat seal layer used in the present invention may be asingle layer or plural layers. An embodiment wherein plural heat seallayers are used in the present invention may be: an embodiment whereinheat seal layers of the same composition are laminated, or an embodimentwherein heat seal layers of different compositions are laminated.

3. Optional Technical Structure

The volume hologram transfer foil of the present invention comprises atleast the volume hologram laminate and the heat seal layer, but mayfurther comprise an optional technical structure as needed. As theoptional technical structure used in the present invention, a structurehaving the desired function is appropriately selected according to anapplication of the volume hologram transfer foil of the presentinvention. In particular, as examples of the optional technicalstructure suitably used in the present invention, a separator, aprinting layer (design layer) or a print layer (individual informationnumbering etc.) can be cited.

D. Volume Hologram Label

Next, a volume hologram label of the present invention will beexplained. As explained above, the volume hologram label of the presentinvention comprises: the above-mentioned volume hologram laminate, and abinding layer formed on the volume hologram-laminated part of the volumehologram laminate.

Such volume hologram label of the present invention will be explainedwith reference to the drawings. FIG. 8 is a cross-section viewillustrating one example of the volume hologram label of the presentinvention. As shown in FIG. 8, a volume hologram label 230 comprises:the above-mentioned volume hologram laminate 210, and a binding layer231 formed on a volume hologram-laminated part 22 of the volume hologramlaminate 210.

According to the present invention, because the volume hologram laminateof the present invention is used, by arbitrary controlling therespective periods of interference fringes formed on the volume hologramlayer and the resin layer of the volume hologram laminate, it ispossible to obtain a volume hologram label to which the volume hologramthat can regenerate the bright hologram image at an arbitrary wavelengthcan be stuck.

The volume hologram label of the present invention comprises at leastthe volume hologram laminate and the binding layer, and may compriseother technical structure as needed. Hereinafter, the respectivetechnical structure used for the volume hologram label of the presentinvention will be explained in turn.

1. Volume Hologram Laminate

First, a volume hologram laminate used in the present invention will beexplained. The volume hologram laminate used in the present inventionrelates to the above-mentioned embodiment. Thus, the volume hologramlaminate used in the present invention is the same to the one explainedin the above-mentioned section of “B. Volume Hologram Laminate”.

2. Adhesion Layer

Next, an adhesion layer used in the present invention will be explained.A binding agent constituting the adhesion layer used in the presentinvention may be a heat seal agent or a common pressure-sensitivebinding agent. Here, as those to be explained later in the section of“E. Volume Hologram Laminate (Second Embodiment)” may be used as theadhesive agent for the present invention, explanation here is omitted.

A thickness of the binding layer is preferably within the range of 4 μmto 200 μm, and more preferably within the range of 5 μm to 100 μm.

E. Volume Hologram Laminate (Second Embodiment)

Next, the volume hologram laminate of the second embodiment of thepresent invention will be explained.

The volume hologram laminate of the present embodiment comprises: aresin layer partially provided on a substrate, and a volume hologramlayer laminated on the substrate and formed so as to adjacent to theresin layer, characterized in that a volume hologram is formed on theresin layer, and characterized in that a part of the volume hologramlaminate provided with the resin layer and a part of the volume hologramlaminate provided with no resin layer have different regenerated-centerwavelengths.

FIGS. 9A and 9B are each a cross-section view illustrating the volumehologram laminate of the present invention. The volume hologram laminatecomprises: a resin layer 2 partially provided on a substrate 1, and avolume hologram layer 3, which comprises a volume hologram recordingmaterial that contains a radically polymerizable monomer and a cationicpolymerizable monomer, and which is laminated on the substrate 1 andformed so as to adjacent to the resin layer 2 (FIG. 9A).

Here, in FIG. 9A, an embodiment wherein the substrate 1 and the resinlayer 2 are formed so as to adjacent to each other, but the volumehologram laminate of the present invention is not limited to suchembodiment. For example, the volume hologram laminate of the presentinvention may have an embodiment wherein a primer layer 8 is formedbetween the substrate 1 and the resin layer 2 (FIG. 9B).

The substrate 1 can use a substance such as polyethylene terephthalatewhich can support the resin layer 2 and the volume hologram layer 3. Athickness of the substrate is normally within the range of 2 μm to 200μm, and preferably within the range of 10 μm to 50 μm.

Further, the substrate may be used as a protection film for the volumehologram sticker to be explained later, or may be peeled and removed.When the substrate is used as a protection film, adhesion between thesubstrate and the resin layer or the volume hologram recording materiallayer is necessary. Thus, it is better to conduct a surface treatmentsuch as a corona treatment, an ozonation treatment, a plasma treatment,an ionization radiation treatment, a bichromatic treatment, an anchoringor primer treatment to the substrate surface. As the anchoring agent orthe primer agent, an urethane-based, acrylic-based, ethylene-vinylacetate copolymer-based, and chloroethene-vinyl acetate copolymer-basedagents are cited. Further, when the substrate is peeled and removed, itis better to conduct a demold treatment and to provide the resin layerand the volume hologram layer with or with no protection layer inbetween.

Next, the resin layer 2 is a resin layer having transparency and isobtained by coating a resin solution on a part of the substrate such ason the pattern of logo. As examples of a resin forming the resin layerare identical to those explained in the above-mentioned section of “A.Producing Method of Volume Hologram Laminate”, and polymethylmethacrylate (PMMA) resin is particularly cited here.

Although detailed reason is not clear, when the resin forming the resinlayer is a resin such as a polymethyl methacrylate resin, a polyvinylacetate resin, and a polyester resin, it was found possible todifferentiate a regenerated-center wavelength of the part of the volumehologram laminate wherein the resin layer 2 is laminated (substrate1/resin layer 2/volume hologram layer 3′) to a long-wavelength side whencompared to a regenerated-center wavelength of a part of the volumehologram laminate wherein the resin layer is not laminated(substrate/volume hologram layer 3″). The degree of differentiationdepends on the size in the weight average molecular weight of the resin.To differentiate the regenerated-center wavelengths to longer-wavelengthside, the weight average molecular weight is preferably 5,000 to1,000,000, more preferably 5,000 to 500,000 and particularly preferably10,000 to 300,000. The molecular weight of the resin denotes the weightaverage molecular weight obtained by polystyrene conversion measured byGPC (gel permeation chromatography).

The difference between the regenerated-center wavelength of the part ofthe volume hologram laminate provided with the resin layer and theregenerated-center wavelength of the part of the volume hologramlaminate provided with no resin layer is at least 10 nm or more and ispreferably 15 nm or more. The maximum difference is 100 nm.

Further, although detailed reason is not clear, when the resin formingthe resin layer is a resin such as a polyvinyl butyral resin and apolyvinyl acetal resin, it was found possible, unlike the above case, todifferentiate a regenerated-center wavelength of the part provided withthe resin layer to a short-wavelength side when compared to aregenerated-center wavelength of a part provided with no resin layer.Similar to the above, however, the degree of differentiation depends onthe size in the weight average molecular weight of the resin. Todifferentiate the regenerated-center wavelengths to shorter-wavelengthside, the weight average molecular weight is preferably 5,000 to1,000,000, more preferably 5,000 to 500,000 and particularly preferably10,000 to 300,000.

The difference between the regenerated-center wavelength of the part ofthe volume hologram laminate provided with the resin layer and theregenerated-center wavelength of the part of the volume hologramlaminate provided with no resin layer is at least 10 nm or more and ispreferably 15 nm or more. The maximum difference is 100 nm.

Each of the regenerated-center wavelengths of the part provided with aresin layer and the part provided with no resin layer is obtained bymeasuring the transmission using a spectrophotometer (UV-2450™;manufactured by Shimadzu Corporation) to obtain the spectraltransmission curve, and by calculating for the spectral transmissioncurve the regenerated-center wavelength with the diffraction efficiencyand half bandwidth through the following method. It will be explainedwith reference to FIG. 4.

(Diffraction Efficiency)

The peak transmission A and base transmission B of the spectraltransmission are obtained. The diffraction efficiency is obtained by theformula: |B−A|/B (%).

(Half Bandwidth)

Left end (C) and right end (D) of a spectral transmission curve isobtained. The spectral transmission curve is a curb obtained at thetransmission (A+|B−A|/2), in which a half of the difference between thebase transmission A and the peak transmission B is added to the peaktransmission A. Thereby, the bandwidth is obtained by the formula:bandwidth=|D−C| (nm).

(Regenerated-Center Wavelength)

The regenerated-center wavelength is a wavelength (=C+|D−C|/2), in whicha half of the half bandwidth is added to the C obtained through thecalculation of the half bandwidth.

For the resin layer 2, an agent such as an antioxidant, a ultravioletabsorber, a light stabilizer, a thermal stabilizer, a plasticizer, alubricant, an antistat, a flame retardant and a filler may be added tothe extent that it does not affect the above-mentioned difference in theregenerated-center wavelength.

The resin layer 2 is formed by partially coating to the substrate aresin solution, in which a component such as the resin is dissolved to asubstance such as methyl ethyl ketone, toluene, and acetic ether, by aprinting method such as a gravure printing and a screen printing so asthe dried layer thickness becomes 0.1 μm to 10 μm, preferably 0.5 μm to5 μm and particularly preferably 0.5 μm to 3 μm.

The resin layer 2 may be formed so as to contact to the substrate 1, ormay be formed so as to contact to the other layer such as a primer layerwhich is formed in such a manner so as to contact onto the substrate 1.

As the primer layer used in the present invention, a primer layer whichhas the desired function according to the application of the volumehologram laminate of the present invention can be appropriately selectedand it is not particularly restricted.

As shown in FIGS. 9A and 9B, a volume hologram recording material layeris coated directly, without an intermediate layer, onto a resin layer 2formed on a substrate 1.

The volume hologram recording material layer used in the presentinvention contains a photopolymerizable material, and from the viewpoint to enabling the recording of a hologram image with high contrast,it is particularly preferable to combine the radically polymerizablecompound and the cationic polymerizable compound. They are used togetherwith a photo radical polymerization initiator and a photo cationicpolymerization initiator.

Here, the radically polymerizable compound, photo radical polymerizationinitiator, cationic polymerizable compound, and photo cationicpolymerization initiator used in the present invention are the same tothose explained in the above-mentioned section of “A. Method ofProducing Volume Hologram Laminate”, and thus, their explanations areomitted here.

Next, method of producing a volume hologram laminate of the presentinvention will be explained.

The volume hologram laminate of present invention is produced by firstpartially coating on the substrate the resin layer, and then coating andforming on the substrate and the resin layer the volume hologramrecording material layer, comprising a radically polymerizable monomerand a cationic polymerizable monomer, so as the material layer becomesadjacent to each of the substrate and the resin layer.

-   (1) An aging treatment is conducted to the obtained laminate. The    aging treatment is conducted by leaving the laminate at room    temperature or by heating the laminate at 40° C. to 80° C. for 1    hour to 48 hours. By this treatment, monomers and the like in the    volume hologram recording material layer transit to the resin layer    in the layer structure of substrate/resin layer/volume hologram    recording material layer. As it will be explained later in Example    1, IR analysis of the aging treated-resin layer confirms that the    radically polymerizable monomer and the cationic polymerizable    monomer in the volume hologram recording material layer are    transited to the resin layer.-   (2) Then, after the aging treatment of the laminate, a hologram    original master is adhered to the volume hologram recording material    layer side and the resultant is laser irradiated from the substrate    side of the laminate to conduct a hologram exposure. Thereby, a    hologram-recorded volume hologram layer is obtained.

The volume hologram is to record a hologram image by fixing theinterference fringe generated by light interference to the volumehologram layer containing the photopolymerizable material as a fringehaving different refractive indexes. Accordingly, as examples of themethod of recording the volume hologram in the present process, thefollowing methods can be cited: a method of injecting a reference lightbeam from the substrate side of the volume hologram forming substrate,injecting an object light beam from the volume hologram layer side andmaking these lights interfere in the volume hologram layer; and a methodof providing a hologram original master on the volume hologram layer,and making the injected light and the reflected light reflected by thehologram original master interfere in the volume hologram layer byinjecting the light from the substrate side. In particular, the methodof using the above-mentioned hologram original master is preferable.Thereby, the volume hologram is recorded simply and easily.

-   (3) After the hologram exposure, the hologram original master is    peeled and a PET film is laminated to the peeled surface. The    laminate is heated at 50° C. to 150° C. for 5 minutes to 120 minutes    and a UV was irradiated at 500 mJ/cm² to 5,000 mJ/cm². It is thought    that the heating treatment diffuses again part of the polymerizable    monomers, which are remained after the hologram exposure, and that    the other monomers are fixed by the heating treatment-UV irradiation    treatment so that a stable hologram is obtained.

In the present invention, when the resin layer is formed by using apolymethyl methacrylate resin or a polyvinyl acetate resin, it was foundthat the laminated part provided with a structure of the substrate/resinlayer/volume hologram layer has the regenerated-center wavelength to thelonger-wavelength side compare to the regenerated-center wavelength ofthe part of the volume hologram laminate provided with no resin layer.Although the detailed reason is not clear, from the electron microscopecross section photo taken in the Example 1 to be explained later, it isobserved that the interference fringe period (interference fringe gap)of the volume hologram layer was enlarged from the interference fringeperiod (interference fringe gap) of the resin layer. Thus, it is thoughtthat retransmit of monomers from the resin layer to the volume hologramlayer is caused again by the above-mentioned (3) heating process, andthereby the regenerated-center wavelength of the substrate/resinlayer/volume hologram layer laminated part is differentiate to thelonger-wavelength side when compared to the regenerated-centerwavelength of the substrate layer/volume hologram layer laminated partprovided with no resin.

Further, when the resin layer is formed by a polyvinyl butyral resin ora polyvinyl acetal resin, it was found that at the laminated part of thesubstrate/resin layer/volume hologram layer of the volume hologramlaminate, the regenerated-center wavelength thereof is differentiated tothe shorter-wavelength side compare to the part provided with no resinlayer of the volume hologram laminate. The detailed reason is not clear,but it is thought that, with polyvinyl butyral resin layer or polyvinylacetal resin, monomers transit caused by the above-mentioned (3) heatingprocess shows different transit from that of PMMA resin so that theregenerated-center wavelength of the substrate/resin layer/volumehologram layer laminated part is differentiated to theshorter-wavelength compare to the regenerated-center wavelength of thesubstrate/volume hologram layer laminated part provided with no resinlayer.

As explained, the volume hologram laminate of the present invention canbe made to the laminate partially having the part where the respectiveregenerated-center wavelengths are different. Further, even when acontact copy by a single wavelength laser is tried by making theobtained volume hologram laminate as an original master and adhering thevolume hologram recording material layer thereto, parts where therespective regenerated-center wavelengths are different become dark sothat the volume hologram is not easily copied. Thus, a volume hologramlaminate can be made to the volume hologram laminate excellent inforgery prevention.

Next, the volume hologram transferring sheet of the present inventionwill be explained with reference to FIGS. 10 and 12. FIG. 10 illustratesa first volume hologram transferring sheet, wherein an adhesive layer 4is provided on the volume hologram layer 3 of the volume hologramlaminate of FIGS. 9A and 9B. The adhesive layer 4 is apressure-sensitive adhesive layer or a heat seal layer. In particular,FIG. 10 illustrates the case of a volume hologram transfer label whenthe adhesive layer 4 is a pressure-sensitive adhesive layer and apeeling sheet 5 is further laminated. When the adhesive layer 4 is aheat seal layer, a peeling sheet 5 can be omitted and thereby a volumehologram transfer foil is obtained.

FIG. 12 illustrates a second volume hologram transferring sheet, whereina second substrate 7 is provided to the volume hologram layer of thevolume hologram laminate of FIGS. 9A and 9B in a peelable manner, andfurther, an adhesive layer 4 is provided on the resin layer 2 and thevolume hologram layer 3 which are exposed by peeling the substrate 1from the volume hologram laminate of FIGS. 9A and 9B. The adhesive layer4 is a pressure-sensitive adhesive layer or a heat seal layer. Inparticular, FIG. 12 illustrates the case of a volume hologram transferlabel when the adhesive layer 4 is a pressure-sensitive adhesive layerand a peeling sheet 5 is further laminated. When the adhesive layer 4 isa heat seal layer, a peeling sheet 5 can be omitted and thereby a volumehologram transfer foil is obtained.

As the binding agent of the volume hologram transfer label, an acrylateresin or the like can be used. The binding agent is preferably made intoa coating solution by using a substance such as acetic ether, toluene,methyl ethyl ketone, or butyl acetate as a solvent, coated to a peelingsheet by a dried film thickness of 0.5 μm to 20 μm to form apressure-sensitive adhesive layer, and then laminated to the volumehologram layer 3 together with the peeling sheet. As the peeling sheet,other than a common release coated paper, a film, obtained by conductinga release treatment to a film such as a polyethylene terephthalate resinfilm or a polypropylene resin film by a fluorine-based release agent ora silicone-based release agent, may be used.

As a heat seal agent of the volume hologram transfer foil, athermoplastic resin having heat sealing properties, or a resin which canform a heat seal layer as an organic solvent solution are used. Asexamples of the resin which can form a heat seal layer as organicsolvent solution, the following are cited: an ethylene-vinyl acetatecopolymer resin, a polyamide resin, a polyester resin, a polyethyleneresin, an ethylene-isobutylacrylate copolymer resin, a butyral resin, apolyvinyl acetate resin, chloroethene-vinyl acetate copolymer resin,cellulose derivatives, an acrylate resin such as a polymethylmethacrylate resin, a polyvinyl ether resin, a polyurethane resin, apolycarbonate resin, a polypropylene resin, an epoxy resin, a phenolresin, thermoplastic elastomer such as SBS, SIS, SEBS and SEPS, or areactive hot-melt resin. As examples of an organic solution, toluene andmethyl ethyl ketone are cited and they are preferably coated on thevolume hologram layer 3 by dried film thickness of 2 μm to 10 μm with acomma coater, a dye coater, a gravure coater or the like.

The volume hologram sticker of the present invention will be explainedwith reference to FIGS. 11 and 13. As shown in FIG. 11, after peeling apeeling sheet 5 of the volume hologram transferring sheet shown in FIG.10, the volume hologram sticker of the present invention is stuck to anadherend 6 from an adhesive layer 4 side of the volume hologramtransferring sheet, and the substrate 1 is peeled and removed or remainsto become a protection layer.

Further, after peeling a peeling sheet 5 of the volume hologramtransferring sheet shown in FIG. 12, the volume hologram sticker of FIG.13 is stuck to an adherend 6 from an adhesive layer 4 side of the volumehologram transferring sheet, and a second substrate 7 is peeled andremoved or remains to become a protection layer of the volume hologramlayer.

As examples for the adherend 6 of the volume hologram sticker of thepresent invention, a transparent substance such as glass and plastic andan opaque substance can be cited. As examples of plastic, a chloroetheneresin, an acrylate resin, a polystyrene resin, a polyester resin such aspolyethylene terephthalate, or a polycarbonate resin are cited, and theyare particularly suited for a card, sheet and film made of a polyesterresin. The volume hologram transferring sheet may be stuck to anidentification card, a sheet such as an examination admission card, acard such as an ID card, or a booklet such as a passport. Further, thesheet is suitably used as a certification which proves theclassification in security or sanitarian such as fire control andsterilization, or alternatively suitably used for a certificationproving that a proper procedure thereof is taken by a holder of thecertification. In addition, for applications wherein papercertifications have been commonly used to seal and the subject productis a transparent and has flat or quadric surface, the sheet can be usedinstead. Moreover, as a subject to stick the volume hologramtransferring sheet, a film and sheets made of papers, artificial papers,synthetic resins and metals or a product which has a part made ofsubject such as glass are widely used. Still further, by utilizing theunique properties and cube representation properties of the volumehologram, the sheet can also be used for books and magazines such assaddle-stitched weekly magazines, glass window of vehicles, and labelsstuck for premium-version products.

The present invention is not limited to the above-mentioned embodiments.The embodiments are merely examples, and any one having thesubstantially same configuration as the technological idea disclosed inthe claims of the present invention and the same effects is included inthe technological scope of the present invention.

EXAMPLES

Hereinafter, the present invention will be specifically explained withreference to examples, but the embodiments of the present invention arenot limited thereto.

1-1. Example 1

(1) Production of Volume Hologram Forming Substrate

As a substrate, a polyethylene terephthalate (PET) film (Lumirror50T60™; manufactured by Toray Industries, Inc.) of 50 μm thickness wasused. A resin layer forming-coating solution, in which polymethylmethacrylate having 15,000 weight average molecular weights weredissolved into a solvent, was coated by a bar coater to the substrate soas the coated thickness became 2 μm and then dried to form a resinlayer.

Next, volume hologram layer forming-coating solution having thefollowing composition was coated on the resin layer directly using anapplicator so as a dried film thickness became 10 μm, and thereby avolume hologram layer was formed.

(Volume Hologram Layer Forming-Coating Solution) polyvinyl acetate 35weight parts Denka SAKNOHOL SN-08H ®: polymerization degree 800;manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) 1,6-hexanedioldiglycidyl ether 25 weight parts (Denacol EX-212 ®: manufactured byNagase ChemteX Corporation) bisphenoxyethanolfluorene diacrylate 35weight parts (BPEFA ®: manufactured by Osaka Gas Chemicals Co., Ltd.)diaryliodonium salt 4 weight parts (P12074 ®: manufactured by Rhodia)2,5-bis(4-diethylaminobenzylidene) cyclopentanone 1 weight part methylisobutyl ketone 100 weight parts 1-butanol 100 weight parts(2) Hologram Recording process

Next, a hologram original master was laminated on the volume hologramlayer and a laser light of 532 nm was irradiated from the substrate sideby 80 mJ/cm² to record a volume hologram. The hologram original masterwas peeled after the recording and a PET FILM of 50 μm thickness waslaminated on the volume hologram layer.

(3) Substance Transit Process

Subsequently, the resin layer and the volume hologram layer were heated.Heating conditions at this time were 100° C. for 10 minutes.

(4) After-Treatment Process

Next, UV was irradiated to the entire surface to fix the volume hologramlayer, and thereby a volume hologram laminate was obtained.

1-2. Example 2

A volume hologram laminate was produced in the same manner as in Example1 except that polymethyl methacrylate of having 35,000 weight averagemolecular weights was used.

1-3. Example 3

A volume hologram laminate was produced in the same manner as in Example1 except that polymethyl methacrylate of having 100,000 weight averagemolecular weights was used.

1-4. Example 4

A volume hologram laminate was produced in the same manner as in Example1 except that a polyester resin having 40,000 weight average molecularweights (Vylon 270® manufactured by TOYOBO CO., LTD.) was used insteadof polymethyl methacrylate.

1-5. Comparative Example 1

A volume hologram laminate was produced in the same manner as in Example1 except that a resin layer was not formed and a volume hologram layerwas directly formed on a substrate.

1-6. Evaluation of Hologram Recording Properties

The transmission of the each volume hologram laminates obtained in theExamples and the Comparative Example was measured using aspectrophotometer (UV-2450™; manufactures by Shimadzu Corporation), andthe diffraction efficiency, half bandwidth, regenerated-centerwavelength were measured from the spectral transmission curve. Theresults are shown in Table 1.

Respective spectral transmission curves obtained in the Examples 1 to 3and the Comparative Example 1 are shown in FIG. 14.

TABLE 1 Half Bandwidth Diffraction Regenerated-Center (nm) Efficiency(%) Wavelength (nm) Example 1 24 80 532 Example 2 27 81 539 Example 3 2474 544 Example 4 28 74 556 Comparative 28 88 527 Example 1

2-1. Example 5

(1) Production of Volume Hologram Forming Substrate

As a substrate, a polyethylene terephthalate (PET) film (Lumirror50T60™; manufactured by Toray Industries, Inc.) of 50 μm thickness wasused. A resin layer forming-coating solution, in which polymethylmethacrylate having 100,000 weight average molecular weights weredissolved into a methyl ethyl ketone solvent, was coated by a gravureprinting method in pattern to the substrate so as the dried filmthickness of the formed resin layer became 2 μm, and then dried to forma patterned resin layer.

Next, volume hologram layer forming-coating solution having thefollowing composition was coated on the resin layer directly using anapplicator so as a dried film thickness became 10 μm, and thereby avolume hologram layer was formed.

(Volume Hologram Layer Forming-Coating Solution) polyvinyl acetate(Denka SAKNOHOL SN-08H ®: 35 weight parts polymerization degree 800;manufactured by Denki Kagaku Kogyo Kabushiki Kaisha) 1,6-hexanedioldiglycidyl ether (Denacol 25 weight part EX-212 ®: manufactured byNagase ChemteX Corporation) bisphenoxyethanolfluorene diacrylate(BPEFA ®: 35 weight parts manufactured by Osaka Gas Chemicals Co., Ltd.)diaryliodonium salt (P12074 ®: manufactured 4 weight parts by Rhodia)2,5-bis(4-diethylaminobenzylidene) cyclopentanone 1 weight part methylisobutyl ketone 100 weight parts 1-butanol 100 weight parts(2) Aging Process

The obtained volume hologram laminate was left at room temperature for24 hours and an aging treatment was conducted. After the agingtreatment, the resin layer was analyzed by an IR analyzing device(FT/IR-610 manufactured by JASCO Corporation) and it was confirmed that1,6-hexanediol diglycidyl ether and bisphenoxyethanolfluorene diacrylatewere contained.

(3) Hologram Recording Process

A hologram original master was laminated on the volume hologram layer ofthe volume hologram laminate and a laser light of 532 nm was irradiatedfrom the substrate side by 80 mJ/cm² to record a volume hologram. Thehologram original master was peeled after the recording and a PET filmof 50 μm thickness was laminated on the volume hologram layer.

(4) Heating Treatment-UV Irradiation Treatment Process

The volume hologram laminate with the hologram recorded was heatingtreated at 100° C. for 10 minutes. UV (3,000 mJ/cm²) was then irradiatedthereto entirely to fix the hologram, and thereby a volume hologramlaminate was obtained.

FIG. 15 is a 70%-zoomed copy of scanning electron micrograph (15,000times) of the vertical cross section in the resin layer laminated partof the volume hologram laminate obtained. The references made in FIG. 15are as follows: 1 is a substrate, 2 is a resin layer and 3 is a volumehologram layer. It can be observed that interference fringes arerecorded in the resin layer 2 by the gap of 116 nm and interferencefringes are recorded in the volume hologram layer 3 by the gap of 186nm.

Results of measuring the transmissions of the part where the resin layeris patterned and the part where the resin layer is not patterned, by aspectrophotometer (UV-2450™; manufacture by Shimadzu Corporation) areshown in FIG. 16 as the spectral transmission curves.

The regenerated-center wavelength of the spectral transmission curve (A)of the part where the resin layer is patterned was 544 nm and theregenerated-center wavelength of the spectral transmission curve (B) thepart where the resin layer is not patterned was 527 nm.

(Forgery Prevention Properties)

The above-mentioned volume hologram layer forming-coating solution wascoated on a PET film of 50 μm thickness using an applicator so as thedried film thickness became 10 μm, and thereby a laminate was obtained.The above-mentioned volume hologram laminate with the volume hologramrecorded was stuck as an original master to the PET film from the volumehologram recording material layer side of the laminate. The volumehologram was subsequently photographed using a laser light of 532 nm.The obtained photograph showed that the patterned resin layer was darkand the hologram was not well photographed.

2-2. Example 6

A volume hologram laminate with the volume hologram recorded wasobtained in the same manner as in Example 5 except that a methyl ethylketone solution of a polyvinyl acetal resin (S-LEC BH-6®: about 92,000weight average molecular weights: manufactured by SEKISUI CHEMICAL CO.,LTD.) was used as a coating solution for a resin layer.

The transmissions of the part where the resin layer is patterned and thepart where the resin layer is not patterned are measured by using aspectrophotometer (UV-2450™; manufactured by Shimadzu Corporation). FIG.17 shows the obtained spectral transmission curves.

The regenerated-center wavelength of the spectral transmission curve (C)of the part where the resin layer is patterned was 490 nm and theregenerated-center wavelength of the spectral transmission curve (D) thepart where the resin layer is not patterned was 527 nm.

Further, in the same manner as in Example 5, to check the forgeryprevention properties, the obtained volume hologram was photographedusing the above-mentioned volume hologram laminate with the volumehologram recorded as an original master. The obtained photograph showedthat the patterned resin layer was dark and the hologram was not wellphotographed.

2-3. Example 7

A volume hologram laminate with the volume hologram recorded wasobtained in the same manner as in Example 5 except that a methyl ethylketone solution of a polyvinyl acetate resin (about 500,000 weightaverage molecular weights: manufactured by SIGMA-ALDRICH Corp.) was usedas a coating solution for a resin layer.

The transmissions of the part where the resin layer is patterned and thepart where the resin layer is not patterned were measured using aspectrophotometer (UV-2450™; manufactured by Shimadzu Corporation). Theregenerated-center wavelength of the part where the resin layer ispatterned was 554 nm and the regenerated-center wavelength of the partwhere the resin layer is not patterned was 527 nm.

Further, in the same manner as in Example 5, to check the forgeryprevention properties, the obtained volume hologram was photographedusing the above-mentioned volume hologram laminate with the volumehologram recorded as an original master. The obtained photograph showedthat the patterned resin layer was dark and the hologram was not wellphotographed.

2-4. Example 8

A volume hologram laminate with the volume hologram recorded wasobtained in the same manner as in Example 5 except that a methyl ethylketone solution of a polyester resin (Vylon 270®: weight averagemolecular weight 40,000; manufactured by TOYOBO CO., LTD.) was used as acoating solution for a resin layer.

The transmissions of the part where the resin layer is patterned and thepart where the resin layer is not patterned were measured using aspectrophotometer (UV-2450™; manufactured by Shimadzu Corporation). Theregenerated-center wavelength of the part where the resin layer ispatterned was 556 nm and the regenerated-center wavelength of the partwhere the resin layer is not patterned was 527 nm.

Further, in the same manner as in Example 5, to check the forgeryprevention properties, the obtained volume hologram was photographedusing the above-mentioned volume hologram laminate with the volumehologram recorded as an original master. The obtained photograph showedthat the patterned resin layer was dark and the hologram was not wellphotographed.

2-5. Example 9

A binding agent solution of the following components was coated by anapplicator to the volume hologram layer of the volume hologram laminateproduced in Example 5 so as the dried film thickness became 20 μm, theresultant was dried in an oven, and thereby a pressure-sensitiveadhesive layer was formed.

acrylic-based binding agent (Nissetsu PE-118 ®; 100 mass partsmanufactured by NIPPON CARBIDE INDUSTRIES CO., INC.) isocyanate-basedcross-linking agent (Nissetsu  2 mass parts CK-101 ®; manufactured byNIPPON CARBIDE INDUSTRIES CO., INC.) solvent (methyl ethylketone/toluene/acetic  60 mass parts ether = 2/1/1 (mass ratio)Then, a peeling sheet (SPEET® (75 μm); manufactured by TOHCELLO CO.,LTD.) was laminated on the pressure-sensitive adhesive layer, andthereby a volume hologram transferring sheet which is the first volumehologram transferring sheet of the present invention was obtained.

After the peeling sheet was peeled from the volume hologram transferringsheet, it was stuck by a hand laminator to a PVC card, which is anadherend, from the pressure-sensitive adhesive layer side, and thereby avolume hologram sticker of the present invention was obtained. Thesticker, which has different regenerated-center wavelengths in patternform between the part provided with the resin layer and the partprovided with no resin layer of the volume hologram, and is excellent indesign was obtained.

2-6. Example 10

A peelable over protection layer faulting-coating solution having thefollowing composition was coated on an untreated-PET film (Lumirror T60™(25 μm); manufactured by Toray Industries, Inc.) by a bar coater so asthe dried film thickness became 1 μm, dried in an oven, and thereby alaminate of PET film/peelable over protection layer was obtained.

polymethyl methacrylate (weight average molecular 97 mass parts weight100,000) polyethylene wax (weight average molecular weight  3 mass parts10,000) solvent (methyl ethyl ketone/toluene/acetic ether = 2/1/1 60mass parts (mass ratio)

The volume hologram laminate (PET film/resin layer/volume hologramlayer/PET film) obtained in the producing method of the volume hologramlaminate explained in Example 5 and before the process of (4) HeatingTreatment-UV Irradiation Treatment was used. A PET film of the volumehologram layer side was peeled, the laminate was set into a roller of80° C. in a manner such that the volume hologram layer side thereoffaced to the peelable over protection layer surface of the laminate ofPET film/peelable over protection layer obtained above, and thelaminates were pressed in the roller. Afterwards, UV was irradiated tothe entire surface and a volume hologram laminate of PET film/peelableover protection layer/volume hologram layer/resin layer/PET film wasobtained.

A PET film of the resin layer side of the obtained volume hologramlaminate was peeled and a heat seal layer forming-coating solution ofthe following composition was coated by a bar coater on the volumehologram layer and the partially-provided resin layer so as the driedfilm thickness became 4 μm.

polyester resin (Vylonal MD1985 ®; manufactured by 100 mass parts TOYOBOCO., LTD.) solvent (water/isopropyl alcohol = 1/1 (mass ratio)) 100 massparts

The resultant was dried in an oven, and thereby, a volume hologramtransfer foil of the second volume hologram transferring sheet of thepresent invention having PET film/peelable over protection layer/volumehologram layer/resin layer/heat seal layer was obtained.

The obtained volume hologram transfer foil was covered on a PVC card,which is an adherend, from the heat seal layer side using a hot stamper(V-08®; manufactured by Navitas Co., Ltd.) under conditions of transfertemperature 150° C., transfer time 0.5 second and pressing-pressure 125kgf/cm². Then the PET film was peeled and a volume hologram sticker ofpeelable over protection layer/volume hologram layer/resin layer/heatseal layer/PVC card was obtained. The sticker, which has differentregenerated-center wavelengths in pattern form between the part providedwith the resin layer and the part provided with no resin layer of thevolume hologram, and is excellent in design was obtained.

The invention claimed is:
 1. A method of producing a volume hologramlaminate using a volume hologram forming substrate which comprises: asubstrate, a volume hologram layer formed on the substrate andcontaining a photopolymerizable material, a resin layer, formed on thesubstrate so as to contact to the volume hologram layer, containing aresin selected from the group consisting of a polymethyl methacrylateresin, a polyvinyl acetate resin, and a polyester resin, wherein theproducing method comprises processes of: a pre-treatment process oftransiting a polymerizable compound contained in the volume hologramlayer to the resin layer by heating for 1 to 48 hours, a hologramrecording process to record a volume hologram to the volume hologramlayer, a substance transit process of transiting the polymerizablecompound transited to the resin layer from the volume hologram layer byheating for 5 to 120 minutes, and followed by an after-treatment processof polymerizing the polymerizable compound by exposing to ultraviolet.2. The method of producing a volume hologram laminate according to claim1, wherein the photopolymerizable material contains a radicallypolymerizable compound and a cationic polymerizable compound, andwherein the polymerizable compound is the cationic polymerizablecompound.
 3. A method of producing a volume hologram laminate, whereinthe following processes are sequentially carried out to a laminateobtained by partially coating and forming on a portion of a substrate aresin layer consisting of a resin selected from the group consisting ofpolymethyl methacrylate resin, a polyvinyl acetate resin, and apolyester resin and then overcoating the substrate and contacting theresin layer with a volume hologram recording material layer comprising aradically polymerizable monomer and a cationic polymerizable monomer;(1) a process of conducting an aging treatment to the laminate andtransiting the polymerizable monomer of the volume hologram recordingmaterial layer to the resin layer by heating for 1 to 48 hours, (2) ahologram exposing process of exposing the laminate with laser from thesubstrate side, and (3) a hologram fixing process of conducting aheating treatment for 5 to 120 minutes and followed by an ultravioletexposure treatment to move the polymerizable monomer from the resinlayer to the volume hologram recording material layer and fixing ahologram; wherein a volume hologram based on the polymerizable monomertransited from the adjacent volume hologram recording material layer isformed on the resin layer; and further wherein a regenerated-centerwavelength of a part of the laminate provided with the resin layer isdifferentiated to a long-wavelength side when compared to aregenerated-center wavelength of a part of the laminate provided with noresin layer.
 4. A method of producing a volume hologram laminate,wherein the following processes are sequentially carried out to alaminate obtained by partially coating and forming on a portion of asubstrate a resin layer consisting of a resin selected from the groupconsisting of a polyvinyl butyral resin and a polyvinyl acetal resin andthen overcoating the substrate and contacting the resin layer with avolume hologram recording material layer comprising a radicallypolymerizable monomer and a cationic polymerizable monomer; (1) aprocess of conducting an aging treatment to the laminate and transitingthe polymerizable monomer of the volume hologram recording materiallayer to the resin layer by heating for 1 to 48 hours, (2) a hologramexposing process of exposing the laminate with laser from the substrateside, and (3) a hologram fixing process of conducting a heatingtreatment for 5 to 120 minutes and followed by an ultraviolet exposuretreatment to move the polymerizable monomer from the volume hologramrecording material layer to the resin layer and fixing a hologram;wherein a volume hologram based on the polymerizable monomer transitedfrom the adjacent volume hologram recording material layer is formed onthe resin layer; and further wherein a regenerated-center wavelength ofa part of the laminate provided with the resin layer is differentiatedto a short-wavelength side when compared to a regenerated-centerwavelength of a part of the laminate provided with no resin layer.